Convert.ToInt32 方法
定义
重要
一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。 对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。
将指定的值转换为 32 位有符号整数。
重载
| ToInt32(String) |
将数字的指定字符串表示形式转换为等效的 32 位带符号整数。 |
| ToInt32(UInt16) |
将指定的 16 位无符号整数的值转换为等效的 32 位有符号整数。 |
| ToInt32(UInt32) |
将指定的 32 位无符号整数的值转换为等效的 32 位有符号整数。 |
| ToInt32(Single) |
将指定的单精度浮点数的值转换为等效的 32 位带符号整数。 |
| ToInt32(Object, IFormatProvider) |
使用指定的区域性特定格式信息，将指定对象的值转换为 32 位带符号整数。 |
| ToInt32(String, IFormatProvider) |
使用指定的区域性特定格式设置信息，将数字的指定字符串表示形式转换为等效的 32 位带符号整数。 |
| ToInt32(String, Int32) |
将指定基数的数字的字符串表示形式转换为等效的 32 位有符号整数。 |
| ToInt32(UInt64) |
将指定的 64 位无符号整数的值转换为等效的 32 位有符号整数。 |
| ToInt32(SByte) |
将指定的 8 位带符号整数的值转换为等效的 32 位带符号整数。 |
| ToInt32(Object) |
将指定对象的值转换为 32 位带符号整数。 |
| ToInt32(Int64) |
将指定的 64 位有符号整数的值转换为等效的 32 位有符号整数。 |
| ToInt32(Byte) |
将指定的 8 位无符号整数的值转换为等效的 32 位有符号整数。 |
| ToInt32(Char) |
将指定的 Unicode 字符的值转换为等效的 32 位有符号整数。 |
| ToInt32(DateTime) |
调用此方法始终引发 InvalidCastException。 |
| ToInt32(Boolean) |
将指定的布尔值转换为等效的 32 位带符号整数。 |
| ToInt32(Double) |
将指定的双精度浮点数的值转换为等效的 32 位带符号整数。 |
| ToInt32(Int16) |
将指定的 16 位有符号整数的值转换为等效的 32 位有符号整数。 |
| ToInt32(Int32) |
返回指定的 32 位有符号整数；不执行实际的转换。 |
| ToInt32(Decimal) |
将指定的十进制数的值转换为等效的 32 位带符号整数。 |
ToInt32(String)
- Source:
- Convert.cs
- Source:
- Convert.cs
- Source:
- Convert.cs
将数字的指定字符串表示形式转换为等效的 32 位带符号整数。
public:
static int ToInt32(System::String ^ value);public static int ToInt32 (string value);public static int ToInt32 (string? value);static member ToInt32 : string -> intPublic Shared Function ToInt32 (value As String) As Integer参数
- value
- String
包含要转换的数字的字符串。
返回
一个与 value 中数字等效的 32 位带符号整数，如果 value 为 null，则为 0（零）。
例外
value 不由一个可选符号后跟一系列数字 (0-9) 组成。
value 表示小于 Int32.MinValue 或大于 Int32.MaxValue 的数字。
示例
以下示例尝试将数值字符串数组中的每个元素转换为整数。
string[] values = { "One", "1.34e28", "-26.87", "-18", "-6.00",
" 0", "137", "1601.9", Int32.MaxValue.ToString() };
int result;
foreach (string value in values)
{
try {
result = Convert.ToInt32(value);
Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.",
value.GetType().Name, value, result.GetType().Name, result);
}
catch (OverflowException) {
Console.WriteLine("{0} is outside the range of the Int32 type.", value);
}
catch (FormatException) {
Console.WriteLine("The {0} value '{1}' is not in a recognizable format.",
value.GetType().Name, value);
}
}
// The example displays the following output:
// The String value 'One' is not in a recognizable format.
// The String value '1.34e28' is not in a recognizable format.
// The String value '-26.87' is not in a recognizable format.
// Converted the String value '-18' to the Int32 value -18.
// The String value '-6.00' is not in a recognizable format.
// Converted the String value ' 0' to the Int32 value 0.
// Converted the String value '137' to the Int32 value 137.
// The String value '1601.9' is not in a recognizable format.
// Converted the String value '2147483647' to the Int32 value 2147483647.
let values =
[| "One"; "1.34e28"; "-26.87"; "-18"; "-6.00"
" 0"; "137"; "1601.9"; string Int32.MaxValue |]
for value in values do
try
let result = Convert.ToInt32 value
printfn $"Converted the {value.GetType().Name} value {value} to the {result.GetType().Name} value {result}."
with
| :? OverflowException ->
printfn $"{value} is outside the range of the Int32 type."
| :? FormatException ->
printfn $"The {value.GetType().Name} value '{value}' is not in a recognizable format."
// The example displays the following output:
// The String value 'One' is not in a recognizable format.
// The String value '1.34e28' is not in a recognizable format.
// The String value '-26.87' is not in a recognizable format.
// Converted the String value '-18' to the Int32 value -18.
// The String value '-6.00' is not in a recognizable format.
// Converted the String value ' 0' to the Int32 value 0.
// Converted the String value '137' to the Int32 value 137.
// The String value '1601.9' is not in a recognizable format.
// Converted the String value '2147483647' to the Int32 value 2147483647.
Dim values() As String = { "One", "1.34e28", "-26.87", "-18", "-6.00", _
" 0", "137", "1601.9", Int32.MaxValue.ToString() }
Dim result As Integer
For Each value As String In values
Try
result = Convert.ToInt32(value)
Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _
value.GetType().Name, value, result.GetType().Name, result)
Catch e As OverflowException
Console.WriteLine("{0} is outside the range of the Int32 type.", value)
Catch e As FormatException
Console.WriteLine("The {0} value '{1}' is not in a recognizable format.", _
value.GetType().Name, value)
End Try
Next
' The example displays the following output:
' The String value 'One' is not in a recognizable format.
' The String value '1.34e28' is not in a recognizable format.
' The String value '-26.87' is not in a recognizable format.
' Converted the String value '-18' to the Int32 value -18.
' The String value '-6.00' is not in a recognizable format.
' Converted the String value ' 0' to the Int32 value 0.
' Converted the String value '137' to the Int32 value 137.
' The String value '1601.9' is not in a recognizable format.
' Converted the String value '2147483647' to the Int32 value 2147483647.
注解
ToInt32(String)使用 方法等效于将 Int32.Parse(String) 传递给 value 方法。
value 通过使用当前区域性的格式设置约定进行解释。
如果不想在转换失败时处理异常，可以改为调用 Int32.TryParse 方法。 它返回一个 Boolean 值，该值指示转换是成功还是失败。
适用于
ToInt32(UInt16)
- Source:
- Convert.cs
- Source:
- Convert.cs
- Source:
- Convert.cs
重要
此 API 不符合 CLS。
将指定的 16 位无符号整数的值转换为等效的 32 位有符号整数。
public:
static int ToInt32(System::UInt16 value);[System.CLSCompliant(false)]
public static int ToInt32 (ushort value);[<System.CLSCompliant(false)>]
static member ToInt32 : uint16 -> intPublic Shared Function ToInt32 (value As UShort) As Integer参数
- value
- UInt16
要转换的 16 位无符号整数。
返回
一个与 value 等效的 32 位带符号整数。
- 属性
示例
以下示例将 16 位无符号整数数组中的每个元素转换为整数。
ushort[] numbers = { UInt16.MinValue, 121, 340, UInt16.MaxValue };
int result;
foreach (ushort number in numbers)
{
try {
result = Convert.ToInt32(number);
Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
number.GetType().Name, number,
result.GetType().Name, result);
}
catch (OverflowException) {
Console.WriteLine("The {0} value {1} is outside the range of the Int32 type.",
number.GetType().Name, number);
}
}
// The example displays the following output:
// Converted the UInt16 value 0 to the Int32 value 0.
// Converted the UInt16 value 121 to the Int32 value 121.
// Converted the UInt16 value 340 to the Int32 value 340.
// Converted the UInt16 value 65535 to the Int32 value 65535.
let numbers =
[| UInt16.MinValue; 121us; 340us; UInt16.MaxValue |]
for number in numbers do
try
let result = Convert.ToInt32 number
printfn $"Converted the {number.GetType().Name} value {number} to the {result.GetType().Name} value {result}."
with :? OverflowException ->
printfn $"The {number.GetType().Name} value {number} is outside the range of the Int32 type."
// The example displays the following output:
// Converted the UInt16 value 0 to the Int32 value 0.
// Converted the UInt16 value 121 to the Int32 value 121.
// Converted the UInt16 value 340 to the Int32 value 340.
// Converted the UInt16 value 65535 to the Int32 value 65535.
Dim numbers() As UShort = { UInt16.MinValue, 121, 340, UInt16.MaxValue }
Dim result As Integer
For Each number As UShort In numbers
Try
result = Convert.ToInt32(number)
Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
number.GetType().Name, number, _
result.GetType().Name, result)
Catch e As OverflowException
Console.WriteLine("The {0} value {1} is outside the range of the Int32 type.", _
number.GetType().Name, number)
End Try
Next
' The example displays the following output:
' Converted the UInt16 value 0 to the Int32 value 0.
' Converted the UInt16 value 121 to the Int32 value 121.
' Converted the UInt16 value 340 to the Int32 value 340.
' Converted the UInt16 value 65535 to the Int32 value 65535.
适用于
ToInt32(UInt32)
- Source:
- Convert.cs
- Source:
- Convert.cs
- Source:
- Convert.cs
重要
此 API 不符合 CLS。
将指定的 32 位无符号整数的值转换为等效的 32 位有符号整数。
public:
static int ToInt32(System::UInt32 value);[System.CLSCompliant(false)]
public static int ToInt32 (uint value);[<System.CLSCompliant(false)>]
static member ToInt32 : uint32 -> intPublic Shared Function ToInt32 (value As UInteger) As Integer参数
- value
- UInt32
要转换的 32 位无符号整数。
返回
一个与 value 等效的 32 位带符号整数。
- 属性
例外
value 大于 Int32.MaxValue。
示例
以下示例尝试将无符号整数数组中的每个元素转换为有符号整数。
uint[] numbers = { UInt32.MinValue, 121, 340, UInt32.MaxValue };
int result;
foreach (uint number in numbers)
{
try {
result = Convert.ToInt32(number);
Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
number.GetType().Name, number,
result.GetType().Name, result);
}
catch (OverflowException) {
Console.WriteLine("The {0} value {1} is outside the range of the Int32 type.",
number.GetType().Name, number);
}
}
// The example displays the following output:
// Converted the UInt32 value 0 to the Int32 value 0.
// Converted the UInt32 value 121 to the Int32 value 121.
// Converted the UInt32 value 340 to the Int32 value 340.
// The UInt32 value 4294967295 is outside the range of the Int32 type.
let numbers =
[| UInt32.MinValue; 121u; 340u; UInt32.MaxValue |]
for number in numbers do
try
let result = Convert.ToInt32 number
printfn $"Converted the {number.GetType().Name} value {number} to the {result.GetType().Name} value {result}."
with :? OverflowException ->
printfn $"The {number.GetType().Name} value {number} is outside the range of the Int32 type."
// The example displays the following output:
// Converted the UInt32 value 0 to the Int32 value 0.
// Converted the UInt32 value 121 to the Int32 value 121.
// Converted the UInt32 value 340 to the Int32 value 340.
// The UInt32 value 4294967295 is outside the range of the Int32 type.
Dim numbers() As UInteger = { UInt32.MinValue, 121, 340, UInt32.MaxValue }
Dim result As Integer
For Each number As UInteger In numbers
Try
result = Convert.ToInt32(number)
Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
number.GetType().Name, number, _
result.GetType().Name, result)
Catch e As OverflowException
Console.WriteLine("The {0} value {1} is outside the range of the Int32 type.", _
number.GetType().Name, number)
End Try
Next
' The example displays the following output:
' Converted the UInt32 value 0 to the Int32 value 0.
' Converted the UInt32 value 121 to the Int32 value 121.
' Converted the UInt32 value 340 to the Int32 value 340.
' The UInt32 value 4294967295 is outside the range of the Int32 type.
适用于
ToInt32(Single)
- Source:
- Convert.cs
- Source:
- Convert.cs
- Source:
- Convert.cs
将指定的单精度浮点数的值转换为等效的 32 位带符号整数。
public:
static int ToInt32(float value);public static int ToInt32 (float value);static member ToInt32 : single -> intPublic Shared Function ToInt32 (value As Single) As Integer参数
- value
- Single
要转换的单精度浮点数。
返回
value，舍入为最接近的 32 位有符号整数。 如果 value 为两个整数中间的数字，则返回二者中的偶数；即 4.5 转换为 4，而 5.5 转换为 6。
例外
value 大于 Int32.MaxValue 或小于 Int32.MinValue。
示例
以下示例尝试将值数组 Single 中的每个元素转换为整数。
float[] values= { Single.MinValue, -1.38e10f, -1023.299f, -12.98f,
0f, 9.113e-16f, 103.919f, 17834.191f, Single.MaxValue };
int result;
foreach (float value in values)
{
try {
result = Convert.ToInt32(value);
Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
value.GetType().Name, value, result.GetType().Name, result);
}
catch (OverflowException) {
Console.WriteLine("{0} is outside the range of the Int32 type.", value);
}
}
// The example displays the following output:
// -3.40282346638529E+38 is outside the range of the Int32 type.
// -13799999488 is outside the range of the Int32 type.
// Converted the Double value -1023.29901123047 to the Int32 value -1023.
// Converted the Double value -12.9799995422363 to the Int32 value -13.
// Converted the Double value 0 to the Int32 value 0.
// Converted the Double value 9.11299983940444E-16 to the Int32 value 0.
// Converted the Double value 103.918998718262 to the Int32 value 104.
// Converted the Double value 17834.19140625 to the Int32 value 17834.
// 3.40282346638529E+38 is outside the range of the Int32 type.
let values =
[| Single.MinValue; -1.38e10f; -1023.299f; -12.98f
0f; 9.113e-16f; 103.919f; 17834.191f; Single.MaxValue |]
for value in values do
try
let result = Convert.ToInt32 value
printfn $"Converted the {value.GetType().Name} value {value} to the {result.GetType().Name} value {result}."
with :? OverflowException ->
printfn $"{value} is outside the range of the Int32 type."
// The example displays the following output:
// -3.40282346638529E+38 is outside the range of the Int32 type.
// -13799999488 is outside the range of the Int32 type.
// Converted the Double value -1023.29901123047 to the Int32 value -1023.
// Converted the Double value -12.9799995422363 to the Int32 value -13.
// Converted the Double value 0 to the Int32 value 0.
// Converted the Double value 9.11299983940444E-16 to the Int32 value 0.
// Converted the Double value 103.918998718262 to the Int32 value 104.
// Converted the Double value 17834.19140625 to the Int32 value 17834.
// 3.40282346638529E+38 is outside the range of the Int32 type.
Dim values() As Single = { Single.MinValue, -1.38e10, -1023.299, -12.98, _
0, 9.113e-16, 103.919, 17834.191, Single.MaxValue }
Dim result As Integer
For Each value As Single In values
Try
result = Convert.ToInt32(value)
Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
value.GetType().Name, value, result.GetType().Name, result)
Catch e As OverflowException
Console.WriteLine("{0} is outside the range of the Int32 type.", value)
End Try
Next
' The example displays the following output:
' -3.40282346638529E+38 is outside the range of the Int32 type.
' -13799999488 is outside the range of the Int32 type.
' Converted the Double value -1023.29901123047 to the Int32 value -1023.
' Converted the Double value -12.9799995422363 to the Int32 value -13.
' Converted the Double value 0 to the Int32 value 0.
' Converted the Double value 9.11299983940444E-16 to the Int32 value 0.
' Converted the Double value 103.918998718262 to the Int32 value 104.
' Converted the Double value 17834.19140625 to the Int32 value 17834.
' 3.40282346638529E+38 is outside the range of the Int32 type.
另请参阅
适用于
ToInt32(Object, IFormatProvider)
- Source:
- Convert.cs
- Source:
- Convert.cs
- Source:
- Convert.cs
使用指定的区域性特定格式信息，将指定对象的值转换为 32 位带符号整数。
public:
static int ToInt32(System::Object ^ value, IFormatProvider ^ provider);public static int ToInt32 (object value, IFormatProvider provider);public static int ToInt32 (object? value, IFormatProvider? provider);static member ToInt32 : obj * IFormatProvider -> intPublic Shared Function ToInt32 (value As Object, provider As IFormatProvider) As Integer参数
- value
- Object
一个实现 IConvertible 接口的对象。
- provider
- IFormatProvider
一个提供区域性特定的格式设置信息的对象。
返回
一个与 value 等效的 32 位带符号整数，如果 value 为 null，则为零。
例外
value 的格式不正确。
value 不实现 IConvertible。
value 表示小于 Int32.MinValue 或大于 Int32.MaxValue 的数字。
示例
以下示例定义实现 的 IConvertible 类和实现 的 IFormatProvider类。 实现 IConvertible 的 类的对象保存值数组 Double 。 每个类的 一个 对象将 ToInt32 传递给 方法。 此方法使用实现IFormatProvider的 对象来确定如何计算平均值，返回值数组Double的平均值。
using namespace System;
using namespace System::Collections;
// Define the types of averaging available in the class
// implementing IConvertible.
public enum class AverageType : short
{
None = 0,
GeometricMean = 1,
ArithmeticMean = 2,
Median = 3
};
// Pass an instance of this class to methods that require an
// IFormatProvider. The class instance determines the type of
// average to calculate.
ref class AverageInfo: public IFormatProvider
{
protected:
AverageType AvgType;
public:
// Specify the type of averaging in the constructor.
AverageInfo( AverageType avgType )
{
this->AvgType = avgType;
}
// This method returns a reference to the containing object
// if an object of AverageInfo type is requested.
virtual Object^ GetFormat( Type^ argType )
{
if ( argType == AverageInfo::typeid)
return this;
else
return (Object^)0;
}
property AverageType TypeOfAverage
{
// Use this property to set or get the type of averaging.
AverageType get()
{
return this->AvgType;
}
void set( AverageType value )
{
this->AvgType = value;
}
}
};
// This class encapsulates an array of double values and implements
// the IConvertible interface. Most of the IConvertible methods
// return an average of the array elements in one of three types:
// arithmetic mean, geometric mean, or median.
ref class DataSet: public IConvertible
{
private:
static Object^ null = nullptr;
protected:
ArrayList^ data;
AverageInfo^ defaultProvider;
// This method unboxes a boxed double.
double UnBoxDouble( Object^ obj )
{
return *static_cast<double^>(obj);
}
public:
// Construct the object and add an initial list of values.
// Create a default format provider.
DataSet( ... array<Double>^values )
{
data = gcnew ArrayList( (Array^)values );
defaultProvider = gcnew AverageInfo( AverageType::ArithmeticMean );
}
// Add additional values with this method.
int Add( double value )
{
data->Add( value );
return data->Count;
}
property double Item[ int ]
{
// Get, set, and add values with this indexer property.
double get( int index )
{
if ( index >= 0 && index < data->Count )
return UnBoxDouble( data[ index ] );
else
throw gcnew InvalidOperationException( "[DataSet.get] Index out of range." );
}
void set( int index, double value )
{
if ( index >= 0 && index < data->Count )
data[ index ] = value;
else
if ( index == data->Count )
data->Add( value );
else
throw gcnew InvalidOperationException( "[DataSet.set] Index out of range." );
}
}
property int Count
{
// This property returns the number of elements in the object.
int get()
{
return data->Count;
}
}
protected:
// This method calculates the average of the object's elements.
double Average( AverageType avgType )
{
double SumProd;
if ( data->Count == 0 )
return 0.0;
switch ( avgType )
{
case AverageType::GeometricMean:
SumProd = 1.0;
for ( int Index = 0; Index < data->Count; Index++ )
SumProd *= UnBoxDouble( data[ Index ] );
// This calculation will not fail with negative
// elements.
return Math::Sign( SumProd ) * Math::Pow( Math::Abs( SumProd ), 1.0 / data->Count );
case AverageType::ArithmeticMean:
SumProd = 0.0;
for ( int Index = 0; Index < data->Count; Index++ )
SumProd += UnBoxDouble( data[ Index ] );
return SumProd / data->Count;
case AverageType::Median:
if ( data->Count % 2 == 0 )
return (UnBoxDouble( data[ data->Count / 2 ] ) + UnBoxDouble( data[ data->Count / 2 - 1 ] )) / 2.0;
else
return UnBoxDouble( data[ data->Count / 2 ] );
default:
return 0.0;
}
}
// Get the AverageInfo object from the caller's format provider,
// or use the local default.
AverageInfo^ GetAverageInfo( IFormatProvider^ provider )
{
AverageInfo^ avgInfo = nullptr;
if ( provider != nullptr )
avgInfo = static_cast<AverageInfo^>(provider->GetFormat( AverageInfo::typeid ));
if ( avgInfo == nullptr )
return defaultProvider;
else
return avgInfo;
}
// Calculate the average and limit the range.
double CalcNLimitAverage( double min, double max, IFormatProvider^ provider )
{
// Get the format provider and calculate the average.
AverageInfo^ avgInfo = GetAverageInfo( provider );
double avg = Average( avgInfo->TypeOfAverage );
// Limit the range, based on the minimum and maximum values
// for the type.
return avg > max ? max : avg < min ? min : avg;
}
public:
// The following elements are required by IConvertible.
// None of these conversion functions throw exceptions. When
// the data is out of range for the type, the appropriate
// MinValue or MaxValue is used.
virtual TypeCode GetTypeCode()
{
return TypeCode::Object;
}
virtual bool ToBoolean( IFormatProvider^ provider )
{
// ToBoolean is false if the dataset is empty.
if ( data->Count <= 0 )
return false;
// For median averaging, ToBoolean is true if any
// non-discarded elements are nonzero.
else
// For median averaging, ToBoolean is true if any
// non-discarded elements are nonzero.
if ( AverageType::Median == GetAverageInfo( provider )->TypeOfAverage )
{
if ( data->Count % 2 == 0 )
return (UnBoxDouble( data[ data->Count / 2 ] ) != 0.0 || UnBoxDouble( data[ data->Count / 2 - 1 ] ) != 0.0);
else
return UnBoxDouble( data[ data->Count / 2 ] ) != 0.0;
}
// For arithmetic or geometric mean averaging, ToBoolean is
// true if any element of the dataset is nonzero.
else
{
for ( int Index = 0; Index < data->Count; Index++ )
if ( UnBoxDouble( data[ Index ] ) != 0.0 )
return true;
return false;
}
}
virtual Byte ToByte( IFormatProvider^ provider )
{
return Convert::ToByte( CalcNLimitAverage( Byte::MinValue, Byte::MaxValue, provider ) );
}
virtual Char ToChar( IFormatProvider^ provider )
{
return Convert::ToChar( Convert::ToUInt16( CalcNLimitAverage( Char::MinValue, Char::MaxValue, provider ) ) );
}
// Convert to DateTime by adding the calculated average as
// seconds to the current date and time. A valid DateTime is
// always returned.
virtual DateTime ToDateTime( IFormatProvider^ provider )
{
double seconds = Average( GetAverageInfo( provider )->TypeOfAverage );
try
{
return DateTime::Now.AddSeconds( seconds );
}
catch ( ArgumentOutOfRangeException^ )
{
return seconds < 0.0 ? DateTime::MinValue : DateTime::MaxValue;
}
}
virtual Decimal ToDecimal( IFormatProvider^ provider )
{
// The Double conversion rounds Decimal.MinValue and
// Decimal.MaxValue to invalid Decimal values, so the
// following limits must be used.
return Convert::ToDecimal( CalcNLimitAverage( -79228162514264330000000000000.0, 79228162514264330000000000000.0, provider ) );
}
virtual double ToDouble( IFormatProvider^ provider )
{
return Average( GetAverageInfo( provider )->TypeOfAverage );
}
virtual short ToInt16( IFormatProvider^ provider )
{
return Convert::ToInt16( CalcNLimitAverage( Int16::MinValue, Int16::MaxValue, provider ) );
}
virtual int ToInt32( IFormatProvider^ provider )
{
return Convert::ToInt32( CalcNLimitAverage( Int32::MinValue, Int32::MaxValue, provider ) );
}
virtual __int64 ToInt64( IFormatProvider^ provider )
{
// The Double conversion rounds Int64.MinValue and
// Int64.MaxValue to invalid Int64 values, so the following
// limits must be used.
return Convert::ToInt64( CalcNLimitAverage( -9223372036854775000, 9223372036854775000, provider ) );
}
virtual signed char ToSByte( IFormatProvider^ provider )
{
return Convert::ToSByte( CalcNLimitAverage( SByte::MinValue, SByte::MaxValue, provider ) );
}
virtual float ToSingle( IFormatProvider^ provider )
{
return Convert::ToSingle( CalcNLimitAverage( Single::MinValue, Single::MaxValue, provider ) );
}
virtual UInt16 ToUInt16( IFormatProvider^ provider )
{
return Convert::ToUInt16( CalcNLimitAverage( UInt16::MinValue, UInt16::MaxValue, provider ) );
}
virtual UInt32 ToUInt32( IFormatProvider^ provider )
{
return Convert::ToUInt32( CalcNLimitAverage( UInt32::MinValue, UInt32::MaxValue, provider ) );
}
virtual UInt64 ToUInt64( IFormatProvider^ provider )
{
// The Double conversion rounds UInt64.MaxValue to an invalid
// UInt64 value, so the following limit must be used.
return Convert::ToUInt64( CalcNLimitAverage( 0, 18446744073709550000.0, provider ) );
}
virtual Object^ ToType( Type^ conversionType, IFormatProvider^ provider )
{
return Convert::ChangeType( Average( GetAverageInfo( provider )->TypeOfAverage ), conversionType );
}
virtual String^ ToString( IFormatProvider^ provider )
{
AverageType avgType = GetAverageInfo( provider )->TypeOfAverage;
return String::Format( "( {0}: {1:G10} )", avgType, Average( avgType ) );
}
};
// Display a DataSet with three different format providers.
void DisplayDataSet( DataSet^ ds )
{
IFormatProvider^ null = nullptr;
String^ fmt = "{0,-12}{1,20}{2,20}{3,20}";
AverageInfo^ median = gcnew AverageInfo( AverageType::Median );
AverageInfo^ geMean = gcnew AverageInfo( AverageType::GeometricMean );
// Display the dataset elements.
if ( ds->Count > 0 )
{
Console::Write( "\nDataSet: [{0}", ds->Item[ 0 ] );
for ( int iX = 1; iX < ds->Count; iX++ )
Console::Write( ", {0}", ds->Item[ iX ] );
Console::WriteLine( "]\n" );
}
Console::WriteLine( fmt, "Convert::", "Default", "Geometric Mean", "Median" );
Console::WriteLine( fmt, "---------", "-------", "--------------", "------" );
Console::WriteLine( fmt, "ToBoolean", Convert::ToBoolean( ds, null ), Convert::ToBoolean( ds, geMean ), Convert::ToBoolean( ds, median ) );
Console::WriteLine( fmt, "ToByte", Convert::ToByte( ds, null ), Convert::ToByte( ds, geMean ), Convert::ToByte( ds, median ) );
Console::WriteLine( fmt, "ToChar", Convert::ToChar( ds, null ), Convert::ToChar( ds, geMean ), Convert::ToChar( ds, median ) );
Console::WriteLine( "{0,-12}{1,20:yyyy-MM-dd HH:mm:ss}"
"{2,20:yyyy-MM-dd HH:mm:ss}{3,20:yyyy-MM-dd HH:mm:ss}", "ToDateTime", Convert::ToDateTime( ds, null ), Convert::ToDateTime( ds, geMean ), Convert::ToDateTime( ds, median ) );
Console::WriteLine( fmt, "ToDecimal", Convert::ToDecimal( ds, null ), Convert::ToDecimal( ds, geMean ), Convert::ToDecimal( ds, median ) );
Console::WriteLine( fmt, "ToDouble", Convert::ToDouble( ds, null ), Convert::ToDouble( ds, geMean ), Convert::ToDouble( ds, median ) );
Console::WriteLine( fmt, "ToInt16", Convert::ToInt16( ds, null ), Convert::ToInt16( ds, geMean ), Convert::ToInt16( ds, median ) );
Console::WriteLine( fmt, "ToInt32", Convert::ToInt32( ds, null ), Convert::ToInt32( ds, geMean ), Convert::ToInt32( ds, median ) );
Console::WriteLine( fmt, "ToInt64", Convert::ToInt64( ds, null ), Convert::ToInt64( ds, geMean ), Convert::ToInt64( ds, median ) );
Console::WriteLine( fmt, "ToSByte", Convert::ToSByte( ds, null ), Convert::ToSByte( ds, geMean ), Convert::ToSByte( ds, median ) );
Console::WriteLine( fmt, "ToSingle", Convert::ToSingle( ds, null ), Convert::ToSingle( ds, geMean ), Convert::ToSingle( ds, median ) );
Console::WriteLine( fmt, "ToUInt16", Convert::ToUInt16( ds, null ), Convert::ToUInt16( ds, geMean ), Convert::ToUInt16( ds, median ) );
Console::WriteLine( fmt, "ToUInt32", Convert::ToUInt32( ds, null ), Convert::ToUInt32( ds, geMean ), Convert::ToUInt32( ds, median ) );
Console::WriteLine( fmt, "ToUInt64", Convert::ToUInt64( ds, null ), Convert::ToUInt64( ds, geMean ), Convert::ToUInt64( ds, median ) );
}
int main()
{
Console::WriteLine( "This example of the "
"Convert::To<Type>( Object*, IFormatProvider* ) methods "
"\ngenerates the following output. The example "
"displays the values \nreturned by the methods, "
"using several IFormatProvider objects.\n" );
// To call a [ParamArray] method in C++, you cannot just
// list the parameters, you need to build an array.
array<Double>^dataElem = gcnew array<Double>(6);
dataElem[ 0 ] = 10.5;
dataElem[ 1 ] = 22.2;
dataElem[ 2 ] = 45.9;
dataElem[ 3 ] = 88.7;
dataElem[ 4 ] = 156.05;
dataElem[ 5 ] = 297.6;
DataSet^ ds1 = gcnew DataSet( dataElem );
DisplayDataSet( ds1 );
dataElem = gcnew array<Double>(5);
dataElem[ 0 ] = 359999.95;
dataElem[ 1 ] = 425000;
dataElem[ 2 ] = 499999.5;
dataElem[ 3 ] = 775000;
dataElem[ 4 ] = 1695000;
DataSet^ ds2 = gcnew DataSet( dataElem );
DisplayDataSet( ds2 );
}
/*
This example of the Convert::To<Type>( Object*, IFormatProvider* ) methods
generates the following output. The example displays the values
returned by the methods, using several IFormatProvider objects.
DataSet: [10.5, 22.2, 45.9, 88.7, 156.05, 297.6]
Convert:: Default Geometric Mean Median
--------- ------- -------------- ------
ToBoolean True True True
ToByte 103 59 67
ToChar g ; C
ToDateTime 2003-05-13 15:30:23 2003-05-13 15:29:39 2003-05-13 15:29:47
ToDecimal 103.491666666667 59.4332135445164 67.3
ToDouble 103.491666666667 59.4332135445164 67.3
ToInt16 103 59 67
ToInt32 103 59 67
ToInt64 103 59 67
ToSByte 103 59 67
ToSingle 103.4917 59.43321 67.3
ToUInt16 103 59 67
ToUInt32 103 59 67
ToUInt64 103 59 67
DataSet: [359999.95, 425000, 499999.5, 775000, 1695000]
Convert:: Default Geometric Mean Median
--------- ------- -------------- ------
ToBoolean True True True
ToByte 255 255 255
ToChar ? ? ?
ToDateTime 2003-05-22 08:05:19 2003-05-20 22:54:57 2003-05-19 10:21:59
ToDecimal 750999.89 631577.237188435 499999.5
ToDouble 750999.89 631577.237188435 499999.5
ToInt16 32767 32767 32767
ToInt32 751000 631577 500000
ToInt64 751000 631577 500000
ToSByte 127 127 127
ToSingle 750999.9 631577.3 499999.5
ToUInt16 65535 65535 65535
ToUInt32 751000 631577 500000
ToUInt64 751000 631577 500000
*/
using System;
using System.Collections;
// Define the types of averaging available in the class
// implementing IConvertible.
public enum AverageType : short
{
None = 0,
GeometricMean = 1,
ArithmeticMean = 2,
Median = 3
};
// Pass an instance of this class to methods that require an
// IFormatProvider. The class instance determines the type of
// average to calculate.
public class AverageInfo : IFormatProvider
{
protected AverageType AvgType;
// Specify the type of averaging in the constructor.
public AverageInfo( AverageType avgType )
{
this.AvgType = avgType;
}
// This method returns a reference to the containing object
// if an object of AverageInfo type is requested.
public object GetFormat( Type argType )
{
if ( argType == typeof( AverageInfo ) )
return this;
else
return null;
}
// Use this property to set or get the type of averaging.
public AverageType TypeOfAverage
{
get { return this.AvgType; }
set { this.AvgType = value; }
}
}
// This class encapsulates an array of double values and implements
// the IConvertible interface. Most of the IConvertible methods
// return an average of the array elements in one of three types:
// arithmetic mean, geometric mean, or median.
public class DataSet : IConvertible
{
protected ArrayList data;
protected AverageInfo defaultProvider;
// Construct the object and add an initial list of values.
// Create a default format provider.
public DataSet( params double[ ] values )
{
data = new ArrayList( values );
defaultProvider =
new AverageInfo( AverageType.ArithmeticMean );
}
// Add additional values with this method.
public int Add( double value )
{
data.Add( value );
return data.Count;
}
// Get, set, and add values with this indexer property.
public double this[ int index ]
{
get
{
if( index >= 0 && index < data.Count )
return (double)data[ index ];
else
throw new InvalidOperationException(
"[DataSet.get] Index out of range." );
}
set
{
if( index >= 0 && index < data.Count )
data[ index ] = value;
else if( index == data.Count )
data.Add( value );
else
throw new InvalidOperationException(
"[DataSet.set] Index out of range." );
}
}
// This property returns the number of elements in the object.
public int Count
{
get { return data.Count; }
}
// This method calculates the average of the object's elements.
protected double Average( AverageType avgType )
{
double SumProd;
if( data.Count == 0 )
return 0.0;
switch( avgType )
{
case AverageType.GeometricMean:
SumProd = 1.0;
for( int Index = 0; Index < data.Count; Index++ )
SumProd *= (double)data[ Index ];
// This calculation will not fail with negative
// elements.
return Math.Sign( SumProd ) * Math.Pow(
Math.Abs( SumProd ), 1.0 / data.Count );
case AverageType.ArithmeticMean:
SumProd = 0.0;
for( int Index = 0; Index < data.Count; Index++ )
SumProd += (double)data[ Index ];
return SumProd / data.Count;
case AverageType.Median:
if( data.Count % 2 == 0 )
return ( (double)data[ data.Count / 2 ] +
(double)data[ data.Count / 2 - 1 ] ) / 2.0;
else
return (double)data[ data.Count / 2 ];
default:
return 0.0;
}
}
// Get the AverageInfo object from the caller's format provider,
// or use the local default.
protected AverageInfo GetAverageInfo( IFormatProvider provider )
{
AverageInfo avgInfo = null;
if( provider != null )
avgInfo = (AverageInfo)provider.GetFormat(
typeof( AverageInfo ) );
if ( avgInfo == null )
return defaultProvider;
else
return avgInfo;
}
// Calculate the average and limit the range.
protected double CalcNLimitAverage( double min, double max,
IFormatProvider provider )
{
// Get the format provider and calculate the average.
AverageInfo avgInfo = GetAverageInfo( provider );
double avg = Average( avgInfo.TypeOfAverage );
// Limit the range, based on the minimum and maximum values
// for the type.
return avg > max ? max : avg < min ? min : avg;
}
// The following elements are required by IConvertible.
// None of these conversion functions throw exceptions. When
// the data is out of range for the type, the appropriate
// MinValue or MaxValue is used.
public TypeCode GetTypeCode( )
{
return TypeCode.Object;
}
public bool ToBoolean( IFormatProvider provider )
{
// ToBoolean is false if the dataset is empty.
if( data.Count <= 0 )
{
return false;
}
// For median averaging, ToBoolean is true if any
// non-discarded elements are nonzero.
else if( AverageType.Median ==
GetAverageInfo( provider ).TypeOfAverage )
{
if (data.Count % 2 == 0 )
return ( (double)data[ data.Count / 2 ] != 0.0 ||
(double)data[ data.Count / 2 - 1 ] != 0.0 );
else
return (double)data[ data.Count / 2 ] != 0.0;
}
// For arithmetic or geometric mean averaging, ToBoolean is
// true if any element of the dataset is nonzero.
else
{
for( int Index = 0; Index < data.Count; Index++ )
if( (double)data[ Index ] != 0.0 )
return true;
return false;
}
}
public byte ToByte( IFormatProvider provider )
{
return Convert.ToByte( CalcNLimitAverage(
Byte.MinValue, Byte.MaxValue, provider ) );
}
public char ToChar( IFormatProvider provider )
{
return Convert.ToChar( Convert.ToUInt16( CalcNLimitAverage(
Char.MinValue, Char.MaxValue, provider ) ) );
}
// Convert to DateTime by adding the calculated average as
// seconds to the current date and time. A valid DateTime is
// always returned.
public DateTime ToDateTime( IFormatProvider provider )
{
double seconds =
Average( GetAverageInfo( provider ).TypeOfAverage );
try
{
return DateTime.Now.AddSeconds( seconds );
}
catch( ArgumentOutOfRangeException )
{
return seconds < 0.0 ? DateTime.MinValue : DateTime.MaxValue;
}
}
public decimal ToDecimal( IFormatProvider provider )
{
// The Double conversion rounds Decimal.MinValue and
// Decimal.MaxValue to invalid Decimal values, so the
// following limits must be used.
return Convert.ToDecimal( CalcNLimitAverage(
-79228162514264330000000000000.0,
79228162514264330000000000000.0, provider ) );
}
public double ToDouble( IFormatProvider provider )
{
return Average( GetAverageInfo(provider).TypeOfAverage );
}
public short ToInt16( IFormatProvider provider )
{
return Convert.ToInt16( CalcNLimitAverage(
Int16.MinValue, Int16.MaxValue, provider ) );
}
public int ToInt32( IFormatProvider provider )
{
return Convert.ToInt32( CalcNLimitAverage(
Int32.MinValue, Int32.MaxValue, provider ) );
}
public long ToInt64( IFormatProvider provider )
{
// The Double conversion rounds Int64.MinValue and
// Int64.MaxValue to invalid Int64 values, so the following
// limits must be used.
return Convert.ToInt64( CalcNLimitAverage(
-9223372036854775000, 9223372036854775000, provider ) );
}
public SByte ToSByte( IFormatProvider provider )
{
return Convert.ToSByte( CalcNLimitAverage(
SByte.MinValue, SByte.MaxValue, provider ) );
}
public float ToSingle( IFormatProvider provider )
{
return Convert.ToSingle( CalcNLimitAverage(
Single.MinValue, Single.MaxValue, provider ) );
}
public UInt16 ToUInt16( IFormatProvider provider )
{
return Convert.ToUInt16( CalcNLimitAverage(
UInt16.MinValue, UInt16.MaxValue, provider ) );
}
public UInt32 ToUInt32( IFormatProvider provider )
{
return Convert.ToUInt32( CalcNLimitAverage(
UInt32.MinValue, UInt32.MaxValue, provider ) );
}
public UInt64 ToUInt64( IFormatProvider provider )
{
// The Double conversion rounds UInt64.MaxValue to an invalid
// UInt64 value, so the following limit must be used.
return Convert.ToUInt64( CalcNLimitAverage(
0, 18446744073709550000.0, provider ) );
}
public object ToType( Type conversionType,
IFormatProvider provider )
{
return Convert.ChangeType( Average(
GetAverageInfo( provider ).TypeOfAverage ),
conversionType );
}
public string ToString( IFormatProvider provider )
{
AverageType avgType = GetAverageInfo( provider ).TypeOfAverage;
return String.Format( "( {0}: {1:G10} )", avgType,
Average( avgType ) );
}
}
class IConvertibleProviderDemo
{
// Display a DataSet with three different format providers.
public static void DisplayDataSet( DataSet ds )
{
string fmt = "{0,-12}{1,20}{2,20}{3,20}";
AverageInfo median = new AverageInfo( AverageType.Median );
AverageInfo geMean =
new AverageInfo( AverageType.GeometricMean );
// Display the dataset elements.
if( ds.Count > 0 )
{
Console.Write( "\nDataSet: [{0}", ds[ 0 ] );
for( int iX = 1; iX < ds.Count; iX++ )
Console.Write( ", {0}", ds[ iX ] );
Console.WriteLine( "]\n" );
}
Console.WriteLine( fmt, "Convert.", "Default",
"Geometric Mean", "Median");
Console.WriteLine( fmt, "--------", "-------",
"--------------", "------");
Console.WriteLine( fmt, "ToBoolean",
Convert.ToBoolean( ds, null ),
Convert.ToBoolean( ds, geMean ),
Convert.ToBoolean( ds, median ) );
Console.WriteLine( fmt, "ToByte",
Convert.ToByte( ds, null ),
Convert.ToByte( ds, geMean ),
Convert.ToByte( ds, median ) );
Console.WriteLine( fmt, "ToChar",
Convert.ToChar( ds, null ),
Convert.ToChar( ds, geMean ),
Convert.ToChar( ds, median ) );
Console.WriteLine( "{0,-12}{1,20:yyyy-MM-dd HH:mm:ss}" +
"{2,20:yyyy-MM-dd HH:mm:ss}{3,20:yyyy-MM-dd HH:mm:ss}",
"ToDateTime", Convert.ToDateTime( ds, null ),
Convert.ToDateTime( ds, geMean ),
Convert.ToDateTime( ds, median ) );
Console.WriteLine( fmt, "ToDecimal",
Convert.ToDecimal( ds, null ),
Convert.ToDecimal( ds, geMean ),
Convert.ToDecimal( ds, median ) );
Console.WriteLine( fmt, "ToDouble",
Convert.ToDouble( ds, null ),
Convert.ToDouble( ds, geMean ),
Convert.ToDouble( ds, median ) );
Console.WriteLine( fmt, "ToInt16",
Convert.ToInt16( ds, null ),
Convert.ToInt16( ds, geMean ),
Convert.ToInt16( ds, median ) );
Console.WriteLine( fmt, "ToInt32",
Convert.ToInt32( ds, null ),
Convert.ToInt32( ds, geMean ),
Convert.ToInt32( ds, median ) );
Console.WriteLine( fmt, "ToInt64",
Convert.ToInt64( ds, null ),
Convert.ToInt64( ds, geMean ),
Convert.ToInt64( ds, median ) );
Console.WriteLine( fmt, "ToSByte",
Convert.ToSByte( ds, null ),
Convert.ToSByte( ds, geMean ),
Convert.ToSByte( ds, median ) );
Console.WriteLine( fmt, "ToSingle",
Convert.ToSingle( ds, null ),
Convert.ToSingle( ds, geMean ),
Convert.ToSingle( ds, median ) );
Console.WriteLine( fmt, "ToUInt16",
Convert.ToUInt16( ds, null ),
Convert.ToUInt16( ds, geMean ),
Convert.ToUInt16( ds, median ) );
Console.WriteLine( fmt, "ToUInt32",
Convert.ToUInt32( ds, null ),
Convert.ToUInt32( ds, geMean ),
Convert.ToUInt32( ds, median ) );
Console.WriteLine( fmt, "ToUInt64",
Convert.ToUInt64( ds, null ),
Convert.ToUInt64( ds, geMean ),
Convert.ToUInt64( ds, median ) );
}
public static void Main( )
{
Console.WriteLine( "This example of " +
"the Convert.To<Type>( object, IFormatProvider ) methods " +
"\ngenerates the following output. The example " +
"displays the values \nreturned by the methods, " +
"using several IFormatProvider objects.\n" );
DataSet ds1 = new DataSet(
10.5, 22.2, 45.9, 88.7, 156.05, 297.6 );
DisplayDataSet( ds1 );
DataSet ds2 = new DataSet(
359999.95, 425000, 499999.5, 775000, 1695000 );
DisplayDataSet( ds2 );
}
}
/*
This example of the Convert.To<Type>( object, IFormatProvider ) methods
generates the following output. The example displays the values
returned by the methods, using several IFormatProvider objects.
DataSet: [10.5, 22.2, 45.9, 88.7, 156.05, 297.6]
Convert. Default Geometric Mean Median
-------- ------- -------------- ------
ToBoolean True True True
ToByte 103 59 67
ToChar g ; C
ToDateTime 2003-05-13 15:04:12 2003-05-13 15:03:28 2003-05-13 15:03:35
ToDecimal 103.491666666667 59.4332135445164 67.3
ToDouble 103.491666666667 59.4332135445164 67.3
ToInt16 103 59 67
ToInt32 103 59 67
ToInt64 103 59 67
ToSByte 103 59 67
ToSingle 103.4917 59.43321 67.3
ToUInt16 103 59 67
ToUInt32 103 59 67
ToUInt64 103 59 67
DataSet: [359999.95, 425000, 499999.5, 775000, 1695000]
Convert. Default Geometric Mean Median
-------- ------- -------------- ------
ToBoolean True True True
ToByte 255 255 255
ToChar ? ? ?
ToDateTime 2003-05-22 07:39:08 2003-05-20 22:28:45 2003-05-19 09:55:48
ToDecimal 750999.89 631577.237188435 499999.5
ToDouble 750999.89 631577.237188435 499999.5
ToInt16 32767 32767 32767
ToInt32 751000 631577 500000
ToInt64 751000 631577 500000
ToSByte 127 127 127
ToSingle 750999.9 631577.3 499999.5
ToUInt16 65535 65535 65535
ToUInt32 751000 631577 500000
ToUInt64 751000 631577 500000
*/
open System
open System.Collections
// Define the types of averaging available in the class
// implementing IConvertible.
type AverageType =
| None = 0s
| GeometricMean = 1s
| ArithmeticMean = 2s
| Median = 3s
// Pass an instance of this class to methods that require an
// IFormatProvider. The class instance determines the type of
// average to calculate.
[<AllowNullLiteral>]
type AverageInfo(avgType: AverageType) =
// Use this property to set or get the type of averaging.
member val TypeOfAverage = avgType with get, set
interface IFormatProvider with
// This method returns a reference to the containing object
// if an object of AverageInfo type is requested.
member this.GetFormat(argType: Type) =
if argType = typeof<AverageInfo> then
this
else
null
// This class encapsulates an array of double values and implements
// the IConvertible interface. Most of the IConvertible methods
// an average of the array elements in one of three types:
// arithmetic mean, geometric mean, or median.
type DataSet([<ParamArray>] values: double[]) =
let data = ResizeArray values
let defaultProvider =
AverageInfo AverageType.ArithmeticMean
// Add additional values with this method.
member _.Add(value: double) =
data.Add value
data.Count
// Get, set, and add values with this indexer property.
member _.Item
with get (index) =
if index >= 0 && index < data.Count then
data[index]
else
raise (InvalidOperationException "[DataSet.get] Index out of range.")
and set index value =
if index >= 0 && index < data.Count then
data[index] <- value
elif index = data.Count then
data.Add value
else
raise (InvalidOperationException "[DataSet.set] Index out of range.")
// This property returns the number of elements in the object.
member _.Count =
data.Count
// This method calculates the average of the object's elements.
member _.Average(avgType: AverageType) =
if data.Count = 0 then
0.0
else
match avgType with
| AverageType.GeometricMean ->
let sumProd =
Seq.reduce ( * ) data
// This calculation will not fail with negative
// elements.
(sign sumProd |> float) * Math.Pow(abs sumProd, 1.0 / (float data.Count))
| AverageType.ArithmeticMean ->
Seq.average data
| AverageType.Median ->
if data.Count % 2 = 0 then
(data[data.Count / 2] + data[data.Count / 2 - 1]) / 2.0
else
data[ data.Count / 2]
| _ ->
0.0
// Get the AverageInfo object from the caller's format provider,
// or use the local default.
member _.GetAverageInfo(provider: IFormatProvider) =
let avgInfo =
if provider <> null then
provider.GetFormat typeof<AverageInfo> :?> AverageInfo
else
null
if avgInfo = null then
defaultProvider
else
avgInfo
// Calculate the average and limit the range.
member this.CalcNLimitAverage(min: double, max: double, provider: IFormatProvider) =
// Get the format provider and calculate the average.
let avgInfo = this.GetAverageInfo provider
let avg = this.Average avgInfo.TypeOfAverage
// Limit the range, based on the minimum and maximum values
// for the type.
if avg > max then max elif avg < min then min else avg
// The following elements are required by IConvertible.
interface IConvertible with
// None of these conversion functions throw exceptions. When
// the data is out of range for the type, the appropriate
// MinValue or MaxValue is used.
member _.GetTypeCode() =
TypeCode.Object
member this.ToBoolean(provider: IFormatProvider) =
// ToBoolean is false if the dataset is empty.
if data.Count <= 0 then
false
// For median averaging, ToBoolean is true if any
// non-discarded elements are nonzero.
elif AverageType.Median = this.GetAverageInfo(provider).TypeOfAverage then
if data.Count % 2 = 0 then
(data[data.Count / 2] <> 0.0 || data[data.Count / 2 - 1] <> 0.0)
else
data[data.Count / 2] <> 0.0
// For arithmetic or geometric mean averaging, ToBoolean is
// true if any element of the dataset is nonzero.
else
Seq.exists (fun x -> x <> 0.0) data
member this.ToByte(provider: IFormatProvider) =
Convert.ToByte(this.CalcNLimitAverage(float Byte.MinValue, float Byte.MaxValue, provider) )
member this.ToChar(provider: IFormatProvider) =
Convert.ToChar(Convert.ToUInt16(this.CalcNLimitAverage(float Char.MinValue, float Char.MaxValue, provider) ) )
// Convert to DateTime by adding the calculated average as
// seconds to the current date and time. A valid DateTime is
// always returned.
member this.ToDateTime(provider: IFormatProvider) =
let seconds = this.Average(this.GetAverageInfo(provider).TypeOfAverage)
try
DateTime.Now.AddSeconds seconds
with :? ArgumentOutOfRangeException ->
if seconds < 0.0 then DateTime.MinValue else DateTime.MaxValue
member this.ToDecimal(provider: IFormatProvider) =
// The Double conversion rounds Decimal.MinValue and
// Decimal.MaxValue to invalid Decimal values, so the
// following limits must be used.
Convert.ToDecimal(this.CalcNLimitAverage(-79228162514264330000000000000.0, 79228162514264330000000000000.0, provider) )
member this.ToDouble(provider: IFormatProvider) =
this.Average(this.GetAverageInfo(provider).TypeOfAverage)
member this.ToInt16(provider: IFormatProvider) =
Convert.ToInt16(this.CalcNLimitAverage(float Int16.MinValue, float Int16.MaxValue, provider) )
member this.ToInt32(provider: IFormatProvider) =
Convert.ToInt32(this.CalcNLimitAverage(Int32.MinValue, Int32.MaxValue, provider) )
member this.ToInt64(provider: IFormatProvider) =
// The Double conversion rounds Int64.MinValue and
// Int64.MaxValue to invalid Int64 values, so the following
// limits must be used.
Convert.ToInt64(this.CalcNLimitAverage(-9223372036854775000., 9223372036854775000., provider) )
member this.ToSByte(provider: IFormatProvider) =
Convert.ToSByte(this.CalcNLimitAverage(float SByte.MinValue, float SByte.MaxValue, provider) )
member this.ToSingle(provider: IFormatProvider) =
Convert.ToSingle(this.CalcNLimitAverage(float Single.MinValue, float Single.MaxValue, provider) )
member this.ToUInt16(provider: IFormatProvider) =
Convert.ToUInt16(this.CalcNLimitAverage(float UInt16.MinValue, float UInt16.MaxValue, provider) )
member this.ToUInt32(provider: IFormatProvider) =
Convert.ToUInt32(this.CalcNLimitAverage(float UInt32.MinValue, float UInt32.MaxValue, provider) )
member this.ToUInt64(provider: IFormatProvider) =
// The Double conversion rounds UInt64.MaxValue to an invalid
// UInt64 value, so the following limit must be used.
Convert.ToUInt64(this.CalcNLimitAverage(0, 18446744073709550000.0, provider) )
member this.ToType(conversionType: Type, provider: IFormatProvider) =
Convert.ChangeType(this.Average(this.GetAverageInfo(provider).TypeOfAverage), conversionType)
member this.ToString(provider: IFormatProvider) =
let avgType = this.GetAverageInfo(provider).TypeOfAverage
$"( {avgType}: {this.Average avgType:G10} )"
// Display a DataSet with three different format providers.
let displayDataSet (ds: DataSet) =
let fmt obj1 obj2 obj3 obj4 = printfn $"{obj1,-12}{obj2,20}{obj3,20}{obj4,20}"
let median = AverageInfo AverageType.Median
let geMean =
AverageInfo AverageType.GeometricMean
// Display the dataset elements.
if ds.Count > 0 then
printf $"\nDataSet: [{ds[0]}"
for i = 1 to ds.Count - 1 do
printf $", {ds[i]}"
printfn "]\n"
fmt "Convert." "Default" "Geometric Mean" "Median"
fmt "--------" "-------" "--------------" "------"
fmt "ToBoolean"
(Convert.ToBoolean(ds, null))
(Convert.ToBoolean(ds, geMean))
(Convert.ToBoolean(ds, median))
fmt "ToByte"
(Convert.ToByte(ds, null))
(Convert.ToByte(ds, geMean))
(Convert.ToByte(ds, median))
fmt "ToChar"
(Convert.ToChar(ds, null))
(Convert.ToChar(ds, geMean))
(Convert.ToChar(ds, median))
printfn $"""{"ToDateTime",-12}{Convert.ToDateTime(ds, null).ToString "20:yyyy-MM-dd HH:mm:ss"}{Convert.ToDateTime(ds, geMean).ToString "20:yyyy-MM-dd HH:mm:ss"}{Convert.ToDateTime(ds, median).ToString "20:yyyy-MM-dd HH:mm:ss"}"""
fmt "ToDecimal"
(Convert.ToDecimal(ds, null))
(Convert.ToDecimal(ds, geMean))
(Convert.ToDecimal(ds, median))
fmt "ToDouble"
(Convert.ToDouble(ds, null))
(Convert.ToDouble(ds, geMean))
(Convert.ToDouble(ds, median))
fmt "ToInt16"
(Convert.ToInt16(ds, null))
(Convert.ToInt16(ds, geMean))
(Convert.ToInt16(ds, median))
fmt "ToInt32"
(Convert.ToInt32(ds, null))
(Convert.ToInt32(ds, geMean))
(Convert.ToInt32(ds, median))
fmt "ToInt64"
(Convert.ToInt64(ds, null))
(Convert.ToInt64(ds, geMean))
(Convert.ToInt64(ds, median))
fmt "ToSByte"
(Convert.ToSByte(ds, null))
(Convert.ToSByte(ds, geMean))
(Convert.ToSByte(ds, median))
fmt "ToSingle"
(Convert.ToSingle(ds, null))
(Convert.ToSingle(ds, geMean))
(Convert.ToSingle(ds, median))
fmt "ToUInt16"
(Convert.ToUInt16(ds, null))
(Convert.ToUInt16(ds, geMean))
(Convert.ToUInt16(ds, median))
fmt "ToUInt32"
(Convert.ToUInt32(ds, null))
(Convert.ToUInt32(ds, geMean))
(Convert.ToUInt32(ds, median))
fmt "ToUInt64"
(Convert.ToUInt64(ds, null))
(Convert.ToUInt64(ds, geMean))
(Convert.ToUInt64(ds, median))
printfn
"""This example of the Convert.To<Type>( object, IFormatprovider) methods
generates the following output. The example displays the values
returned by the methods, using several IFormatProvider objects.
"""
let ds1 = DataSet(10.5, 22.2, 45.9, 88.7, 156.05, 297.6)
displayDataSet ds1
let ds2 = DataSet(359999.95, 425000, 499999.5, 775000, 1695000)
displayDataSet ds2
// This example of the Convert.To<Type>( object, IFormatprovider) methods
// generates the following output. The example displays the values
// returned by the methods, using several IFormatProvider objects.
//
// DataSet: [10.5, 22.2, 45.9, 88.7, 156.05, 297.6]
//
// Convert. Default Geometric Mean Median
// -------- ------- -------------- ------
// ToBoolean True True True
// ToByte 103 59 67
// ToChar g ; C
// ToDateTime 2003-05-13 15:04:12 2003-05-13 15:03:28 2003-05-13 15:03:35
// ToDecimal 103.491666666667 59.4332135445164 67.3
// ToDouble 103.491666666667 59.4332135445164 67.3
// ToInt16 103 59 67
// ToInt32 103 59 67
// ToInt64 103 59 67
// ToSByte 103 59 67
// ToSingle 103.4917 59.43321 67.3
// ToUInt16 103 59 67
// ToUInt32 103 59 67
// ToUInt64 103 59 67
//
// DataSet: [359999.95, 425000, 499999.5, 775000, 1695000]
//
// Convert. Default Geometric Mean Median
// -------- ------- -------------- ------
// ToBoolean True True True
// ToByte 255 255 255
// ToChar ? ? ?
// ToDateTime 2003-05-22 07:39:08 2003-05-20 22:28:45 2003-05-19 09:55:48
// ToDecimal 750999.89 631577.237188435 499999.5
// ToDouble 750999.89 631577.237188435 499999.5
// ToInt16 32767 32767 32767
// ToInt32 751000 631577 500000
// ToInt64 751000 631577 500000
// ToSByte 127 127 127
// ToSingle 750999.9 631577.3 499999.5
// ToUInt16 65535 65535 65535
// ToUInt32 751000 631577 500000
// ToUInt64 751000 631577 500000
Imports System.Collections
Module IConvertibleProviderDemo
' Define the types of averaging available in the class
' implementing IConvertible.
Enum AverageType as Short
None = 0
GeometricMean = 1
ArithmeticMean = 2
Median = 3
End Enum
' Pass an instance of this class to methods that require an
' IFormatProvider. The class instance determines the type of
' average to calculate.
Public Class AverageInfo
Implements IFormatProvider
Protected AvgType As AverageType
' Specify the type of averaging in the constructor.
Public Sub New( avgType As AverageType )
Me.AvgType = avgType
End Sub
' This method returns a reference to the containing object
' if an object of AverageInfo type is requested.
Public Function GetFormat( argType As Type ) As Object _
Implements IFormatProvider.GetFormat
If argType Is GetType( AverageInfo ) Then
Return Me
Else
Return Nothing
End If
End Function
' Use this property to set or get the type of averaging.
Public Property TypeOfAverage( ) As AverageType
Get
Return Me.AvgType
End Get
Set( ByVal value as AverageType )
Me.AvgType = value
End Set
End Property
End Class
' This class encapsulates an array of Double values and implements
' the IConvertible interface. Most of the IConvertible methods
' return an average of the array elements in one of three types:
' arithmetic mean, geometric mean, or median.
Public Class DataSet
Implements IConvertible
Protected data As ArrayList
Protected defaultProvider As AverageInfo
' Construct the object and add an initial list of values.
' Create a default format provider.
Public Sub New( ParamArray values( ) As Double )
data = New ArrayList( values )
defaultProvider = New AverageInfo( _
AverageType.ArithmeticMean )
End Sub
' Add additional values with this method.
Public Function Add( value As Double ) As Integer
data.Add( value )
Return data.Count
End Function
' Get, set, and add values with this indexer property.
Default Public Property Item(index As Integer) As Double
Get
If index >= 0 AndAlso index < data.Count Then
Return System.Convert.ToDouble( data( index ) )
Else
Throw New InvalidOperationException( _
"[DataSet.get] Index out of range." )
End If
End Get
Set
If index >= 0 AndAlso index < data.Count Then
data( index ) = value
ElseIf index = data.Count Then
data.Add( value )
Else
Throw New InvalidOperationException( _
"[DataSet.set] Index out of range." )
End If
End Set
End Property
' This property returns the number of elements in the object.
Public ReadOnly Property Count( ) As Integer
Get
Return data.Count
End Get
End Property
' This method calculates the average of the object's elements.
Protected Function Average( ByVal avgType As AverageType ) As Double
Dim SumProd As Double
Dim Index As Integer
If data.Count = 0 Then Return 0.0
Select Case avgType
Case AverageType.GeometricMean
SumProd = 1.0
For Index = 0 To data.Count - 1
SumProd *= data( Index )
Next Index
' This calculation will not fail with negative
' elements.
Return Math.Sign( SumProd ) * Math.Pow( _
Math.Abs( SumProd ), 1.0 / data.Count )
Case AverageType.ArithmeticMean
SumProd = 0.0
For Index = 0 To data.Count - 1
SumProd += data( Index )
Next Index
Return SumProd / data.Count
Case AverageType.Median
If data.Count Mod 2 = 0 Then
Return ( data( data.Count \ 2 ) + _
data( data.Count \ 2 - 1 ) ) / 2.0
Else
Return data( data.Count \ 2 )
End If
End Select
End Function
' Get the AverageInfo object from the caller's format
' provider, or use the local default.
Protected Function GetAverageInfo( _
provider As IFormatProvider ) As AverageInfo
Dim avgInfo As AverageInfo = Nothing
If Not provider Is Nothing Then
avgInfo = provider.GetFormat( GetType( AverageInfo ) )
End If
Return IIf( avgInfo Is Nothing, defaultProvider, avgInfo )
End Function
' Calculate the average and limit the range.
Protected Function CalcNLimitAverage( min As Double, _
max As Double, provider as IFormatProvider ) As Double
' Get the format provider and calculate the average.
Dim avgInfo As AverageInfo = GetAverageInfo( provider )
Dim avg As Double = Average( avgInfo.TypeOfAverage )
' Limit the range, based on the minimum and maximum values
' for the type.
Return IIf( avg > max, max, IIf( avg < min, min, avg ) )
End Function
' The following elements are required by IConvertible.
' None of these conversion functions throw exceptions. When
' the data is out of range for the type, the appropriate
' MinValue or MaxValue is used.
Public Function GetTypeCode( ) As TypeCode _
Implements IConvertible.GetTypeCode
Return TypeCode.Object
End Function
Function ToBoolean( ByVal provider As IFormatProvider ) As _
Boolean Implements IConvertible.ToBoolean
' ToBoolean is false if the dataset is empty.
If data.Count <= 0 Then
Return False
' For median averaging, ToBoolean is true if any
' non-discarded elements are nonzero.
ElseIf AverageType.Median = _
GetAverageInfo( provider ).TypeOfAverage Then
If data.Count Mod 2 = 0 Then
Return ( data( data.Count \ 2 ) <> 0.0 Or _
data( data.Count \ 2 - 1 ) <> 0.0 )
Else
Return data( data.Count \ 2 ) <> 0.0
End If
' For arithmetic or geometric mean averaging, ToBoolean is
' true if any element of the dataset is nonzero.
Else
Dim Index As Integer
For Index = 0 To data.Count - 1
If data( Index ) <> 0.0 Then Return True
Next Index
Return False
End If
End Function
Function ToByte( ByVal provider As IFormatProvider ) As Byte _
Implements IConvertible.ToByte
Return Convert.ToByte( CalcNLimitAverage( _
Byte.MinValue, Byte.MaxValue, provider ) )
End Function
Function ToChar( ByVal provider As IFormatProvider ) As Char _
Implements IConvertible.ToChar
Return Convert.ToChar( Convert.ToUInt16( _
CalcNLimitAverage( 0.0, &HFFFF, provider ) ) )
End Function
' Convert to DateTime by adding the calculated average as
' seconds to the current date and time. A valid DateTime is
' always returned.
Function ToDateTime( ByVal provider As IFormatProvider ) As _
DateTime Implements IConvertible.ToDateTime
Dim seconds As Double = Average( _
GetAverageInfo( provider ).TypeOfAverage )
Try
Return DateTime.Now.AddSeconds( seconds )
Catch ex As ArgumentOutOfRangeException
Return IIf( seconds < 0.0, DateTime.MinValue, _
DateTime.MaxValue )
End Try
End Function
Function ToDecimal( ByVal provider As IFormatProvider ) As _
Decimal Implements IConvertible.ToDecimal
' The Double conversion rounds Decimal.MinValue and
' Decimal.MaxValue to invalid Decimal values, so the
' following limits must be used.
Return Convert.ToDecimal( CalcNLimitAverage( _
-79228162514264330000000000000.0, _
79228162514264330000000000000.0, provider ) )
End Function
Function ToDouble( ByVal provider As IFormatProvider) As _
Double Implements IConvertible.ToDouble
Return Average( GetAverageInfo( provider ).TypeOfAverage )
End Function
Function ToInt16( ByVal provider As IFormatProvider ) As _
Short Implements IConvertible.ToInt16
Return Convert.ToInt16( CalcNLimitAverage( _
Int16.MinValue, Int16.MaxValue, provider ) )
End Function
Function ToInt32( ByVal provider As IFormatProvider ) As _
Integer Implements IConvertible.ToInt32
Return Convert.ToInt32( CalcNLimitAverage( _
Int32.MinValue, Int32.MaxValue, provider ) )
End Function
Function ToInt64( ByVal provider As IFormatProvider ) As Long _
Implements IConvertible.ToInt64
' The Double conversion rounds Int64.MinValue and
' Int64.MaxValue to invalid Long values, so the following
' limits must be used.
Return Convert.ToInt64( CalcNLimitAverage( _
-9223372036854775000, 9223372036854775000, provider ) )
End Function
Function ToSByte( ByVal provider As IFormatProvider ) As _
SByte Implements IConvertible.ToSByte
' SByte.MinValue and SByte.MaxValue are not defined in
' Visual Basic.
Return Convert.ToSByte( CalcNLimitAverage( _
-128, 127, provider ) )
End Function
Function ToSingle( ByVal provider As IFormatProvider ) As _
Single Implements IConvertible.ToSingle
Return Convert.ToSingle( CalcNLimitAverage( _
Single.MinValue, Single.MaxValue, provider ) )
End Function
Function ToUInt16( ByVal provider As IFormatProvider ) As _
UInt16 Implements IConvertible.ToUInt16
' UInt16.MinValue and UInt16.MaxValue are not defined in
' Visual Basic.
Return Convert.ToUInt16( CalcNLimitAverage( _
0, &HFFFF, provider ) )
End Function
Function ToUInt32( ByVal provider As IFormatProvider ) As _
UInt32 Implements IConvertible.ToUInt32
' UInt32.MinValue and UInt32.MaxValue are not defined in
' Visual Basic.
Return Convert.ToUInt32( CalcNLimitAverage( _
0, 4294967295, provider ) )
End Function
Function ToUInt64( ByVal provider As IFormatProvider ) As _
UInt64 Implements IConvertible.ToUInt64
' UInt64.MinValue and UInt64.MaxValue are not defined in
' Visual Basic. The Double conversion would have rounded
' UInt64.MaxValue, so the following limit must be used.
Return Convert.ToUInt64( CalcNLimitAverage( _
0, 18446744073709550000.0, provider ) )
End Function
Function ToType( ByVal conversionType As Type, _
ByVal provider As IFormatProvider) As Object _
Implements IConvertible.ToType
Return Convert.ChangeType( Average( GetAverageInfo( _
provider ).TypeOfAverage ), conversionType )
End Function
Overloads Function ToString( ByVal provider As IFormatProvider _
) As String Implements IConvertible.ToString
Dim avgType as AverageType = _
GetAverageInfo( provider ).TypeOfAverage
Return String.Format( "( {0}: {1:G10} )", avgType, _
Average( avgType ) )
End Function
End Class
' Display a DataSet with three different format providers.
Sub DisplayDataSet( ds As DataSet )
Dim fmt As String = "{0,-12}{1,20}{2,20}{3,20}"
Dim median As AverageInfo = New AverageInfo( AverageType.Median )
Dim geMean As AverageInfo = _
New AverageInfo( AverageType.GeometricMean )
Dim iX As Integer
' Display the dataset elements.
If ds.Count > 0 Then
Console.Write( vbCrLf & "DataSet: [{0}", ds( 0 ) )
For iX = 1 To ds.Count - 1
Console.Write( ", {0}", ds( iX ) )
Next iX
Console.WriteLine( "]" & vbCrLf )
End If
Console.WriteLine( fmt, "Convert.", "Default", _
"Geometric Mean", "Median" )
Console.WriteLine( fmt, "--------", "-------", _
"--------------", "------" )
Console.WriteLine( fmt, "ToBoolean", _
Convert.ToBoolean( ds, Nothing ), _
Convert.ToBoolean( ds, geMean ), _
Convert.ToBoolean( ds, median ) )
Console.WriteLine( fmt, "ToByte", _
Convert.ToByte( ds, Nothing ), _
Convert.ToByte( ds, geMean ), _
Convert.ToByte( ds, median ) )
Console.WriteLine( fmt, "ToChar", _
Convert.ToChar( ds, Nothing ), _
Convert.ToChar( ds, geMean ), _
Convert.ToChar( ds, median ) )
Console.WriteLine( "{0,-12}{1,20:yyyy-MM-dd HH:mm:ss}" & _
"{2,20:yyyy-MM-dd HH:mm:ss}{3,20:yyyy-MM-dd HH:mm:ss}", _
"ToDateTime", Convert.ToDateTime( ds, Nothing ), _
Convert.ToDateTime( ds, geMean ), _
Convert.ToDateTime( ds, median ) )
Console.WriteLine( fmt, "ToDecimal", _
Convert.ToDecimal( ds, Nothing ), _
Convert.ToDecimal( ds, geMean ), _
Convert.ToDecimal( ds, median ) )
Console.WriteLine( fmt, "ToDouble", _
Convert.ToDouble( ds, Nothing ), _
Convert.ToDouble( ds, geMean ), _
Convert.ToDouble( ds, median ) )
Console.WriteLine( fmt, "ToInt16", _
Convert.ToInt16( ds, Nothing ), _
Convert.ToInt16( ds, geMean ), _
Convert.ToInt16( ds, median ) )
Console.WriteLine( fmt, "ToInt32", _
Convert.ToInt32( ds, Nothing ), _
Convert.ToInt32( ds, geMean ), _
Convert.ToInt32( ds, median ) )
Console.WriteLine( fmt, "ToInt64", _
Convert.ToInt64( ds, Nothing ), _
Convert.ToInt64( ds, geMean ), _
Convert.ToInt64( ds, median ) )
Console.WriteLine( fmt, "ToSByte", _
Convert.ToSByte( ds, Nothing ), _
Convert.ToSByte( ds, geMean ), _
Convert.ToSByte( ds, median ) )
Console.WriteLine( fmt, "ToSingle", _
Convert.ToSingle( ds, Nothing ), _
Convert.ToSingle( ds, geMean ), _
Convert.ToSingle( ds, median ) )
Console.WriteLine( fmt, "ToUInt16", _
Convert.ToUInt16( ds, Nothing ), _
Convert.ToUInt16( ds, geMean ), _
Convert.ToUInt16( ds, median ) )
Console.WriteLine( fmt, "ToUInt32", _
Convert.ToUInt32( ds, Nothing ), _
Convert.ToUInt32( ds, geMean ), _
Convert.ToUInt32( ds, median ) )
Console.WriteLine( fmt, "ToUInt64", _
Convert.ToUInt64( ds, Nothing ), _
Convert.ToUInt64( ds, geMean ), _
Convert.ToUInt64( ds, median ) )
End Sub
Sub Main( )
Console.WriteLine( _
"This example of the Convert.To<Type>( Object, " & _
"IFormatProvider ) methods " & vbCrLf & "generates " & _
"the following output. The example displays the " & _
"values " & vbCrLf & "returned by the methods, " & _
"using several IFormatProvider objects." & vbCrLf )
Dim ds1 As New DataSet( 10.5, 22.2, 45.9, 88.7, 156.05, 297.6 )
DisplayDataSet( ds1 )
Dim ds2 As New DataSet( _
359999.95, 425000, 499999.5, 775000, 1695000 )
DisplayDataSet( ds2 )
End Sub
End Module
' This example of the Convert.To<Type>( Object, IFormatProvider ) methods
' generates the following output. The example displays the values
' returned by the methods, using several IFormatProvider objects.
'
' DataSet: [10.5, 22.2, 45.9, 88.7, 156.05, 297.6]
'
' Convert. Default Geometric Mean Median
' -------- ------- -------------- ------
' ToBoolean True True True
' ToByte 103 59 67
' ToChar g ; C
' ToDateTime 2003-05-13 14:52:53 2003-05-13 14:52:09 2003-05-13 14:52:17
' ToDecimal 103.491666666667 59.4332135445164 67.3
' ToDouble 103.491666666667 59.4332135445164 67.3
' ToInt16 103 59 67
' ToInt32 103 59 67
' ToInt64 103 59 67
' ToSByte 103 59 67
' ToSingle 103.4917 59.43321 67.3
' ToUInt16 103 59 67
' ToUInt32 103 59 67
' ToUInt64 103 59 67
'
' DataSet: [359999.95, 425000, 499999.5, 775000, 1695000]
'
' Convert. Default Geometric Mean Median
' -------- ------- -------------- ------
' ToBoolean True True True
' ToByte 255 255 255
' ToChar ? ? ?
' ToDateTime 2003-05-22 07:27:49 2003-05-20 22:17:27 2003-05-19 09:44:29
' ToDecimal 750999.89 631577.237188435 499999.5
' ToDouble 750999.89 631577.237188435 499999.5
' ToInt16 32767 32767 32767
' ToInt32 751000 631577 500000
' ToInt64 751000 631577 500000
' ToSByte 127 127 127
' ToSingle 750999.9 631577.3 499999.5
' ToUInt16 65535 65535 65535
' ToUInt32 751000 631577 500000
' ToUInt64 751000 631577 500000
注解
返回值是调用 IConvertible.ToInt32 基础类型的 value方法的结果。
provider 使用户能够指定有关 的内容 value的区域性特定转换信息。 例如，如果 value 是 一个 String 表示数字的 ， provider 则可提供有关用于表示该数字的表示法的区域性特定信息。
基类型忽略 provider;但是，如果 value 是实现 IConvertible 接口的用户定义类型，可以使用 参数。
适用于
ToInt32(String, IFormatProvider)
- Source:
- Convert.cs
- Source:
- Convert.cs
- Source:
- Convert.cs
使用指定的区域性特定格式设置信息，将数字的指定字符串表示形式转换为等效的 32 位带符号整数。
public:
static int ToInt32(System::String ^ value, IFormatProvider ^ provider);public static int ToInt32 (string value, IFormatProvider provider);public static int ToInt32 (string? value, IFormatProvider? provider);static member ToInt32 : string * IFormatProvider -> intPublic Shared Function ToInt32 (value As String, provider As IFormatProvider) As Integer参数
- value
- String
包含要转换的数字的字符串。
- provider
- IFormatProvider
一个提供区域性特定的格式设置信息的对象。
返回
一个与 value 中数字等效的 32 位带符号整数，如果 value 为 null，则为 0（零）。
例外
value 不由一个可选符号后跟一系列数字 (0-9) 组成。
value 表示小于 Int32.MinValue 或大于 Int32.MaxValue 的数字。
示例
以下示例定义一个自定义 NumberFormatInfo 对象，该对象将字符串“pos”识别为正号，将字符串“neg”识别为负号。 然后，它会尝试使用此提供程序和 NumberFormatInfo 固定区域性的提供程序将数值字符串数组的每个元素转换为整数。
using System;
using System.Globalization;
public class Example
{
public static void Main()
{
// Create a custom NumberFormatInfo object and set its two properties
// used by default in parsing numeric strings.
NumberFormatInfo customProvider = new NumberFormatInfo();
customProvider.NegativeSign = "neg ";
customProvider.PositiveSign = "pos ";
// Add custom and invariant provider to an array of providers.
NumberFormatInfo[] providers = { customProvider, NumberFormatInfo.InvariantInfo };
// Define an array of strings to convert.
string[] numericStrings = { "123456789", "+123456789", "pos 123456789",
"-123456789", "neg 123456789", "123456789.",
"123,456,789", "(123456789)", "2147483648",
"-2147483649" };
// Use each provider to parse all the numeric strings.
for (int ctr = 0; ctr <= 1; ctr++)
{
IFormatProvider provider = providers[ctr];
Console.WriteLine(ctr == 0 ? "Custom Provider:" : "Invariant Provider:");
foreach (string numericString in numericStrings)
{
Console.Write("{0,15} --> ", numericString);
try {
Console.WriteLine("{0,20}", Convert.ToInt32(numericString, provider));
}
catch (FormatException) {
Console.WriteLine("{0,20}", "FormatException");
}
catch (OverflowException) {
Console.WriteLine("{0,20}", "OverflowException");
}
}
Console.WriteLine();
}
}
}
// The example displays the following output:
// Custom Provider:
// 123456789 --> 123456789
// +123456789 --> FormatException
// pos 123456789 --> 123456789
// -123456789 --> FormatException
// neg 123456789 --> -123456789
// 123456789. --> FormatException
// 123,456,789 --> FormatException
// (123456789) --> FormatException
// 2147483648 --> OverflowException
// -2147483649 --> FormatException
//
// Invariant Provider:
// 123456789 --> 123456789
// +123456789 --> 123456789
// pos 123456789 --> FormatException
// -123456789 --> -123456789
// neg 123456789 --> FormatException
// 123456789. --> FormatException
// 123,456,789 --> FormatException
// (123456789) --> FormatException
// 2147483648 --> OverflowException
// -2147483649 --> OverflowException
open System
open System.Globalization
// Create a custom NumberFormatInfo object and set its two properties
// used by default in parsing numeric strings.
let customProvider = NumberFormatInfo()
customProvider.NegativeSign <- "neg "
customProvider.PositiveSign <- "pos "
// Add custom and invariant provider to an array of providers.
let providers =
[| customProvider; NumberFormatInfo.InvariantInfo |]
// Define an array of strings to convert.
let numericStrings =
[| "123456789"; "+123456789"; "pos 123456789"
"-123456789"; "neg 123456789"; "123456789."
"123,456,789"; "(123456789)"; "2147483648"
"-2147483649"; |]
// Use each provider to parse all the numeric strings.
for i = 0 to 1 do
let provider = providers[i]
printfn $"""{if i = 0 then "Custom Provider:" else "Invariant Provider:"}"""
for numericString in numericStrings do
printf $"{numericString,15} --> "
try
printfn $"{Convert.ToInt32(numericString, provider),20}"
with
| :? FormatException ->
printfn "%20s" "FormatException"
| :? OverflowException ->
printfn "%20s" "OverflowException"
printfn ""
// The example displays the following output:
// Custom Provider:
// 123456789 --> 123456789
// +123456789 --> FormatException
// pos 123456789 --> 123456789
// -123456789 --> FormatException
// neg 123456789 --> -123456789
// 123456789. --> FormatException
// 123,456,789 --> FormatException
// (123456789) --> FormatException
// 2147483648 --> OverflowException
// -2147483649 --> FormatException
//
// Invariant Provider:
// 123456789 --> 123456789
// +123456789 --> 123456789
// pos 123456789 --> FormatException
// -123456789 --> -123456789
// neg 123456789 --> FormatException
// 123456789. --> FormatException
// 123,456,789 --> FormatException
// (123456789) --> FormatException
// 2147483648 --> OverflowException
// -2147483649 --> OverflowException
Imports System.Globalization
Module Example
Public Sub Main()
' Create a custom NumberFormatInfo object and set its two properties
' used by default in parsing numeric strings.
Dim customProvider As New NumberFormatInfo()
customProvider.NegativeSign = "neg "
customProvider.PositiveSign = "pos "
' Add custom and invariant provider to an array of providers.
Dim providers() As NumberFormatInfo = { customProvider, NumberFormatInfo.InvariantInfo }
' Define an array of strings to convert.
Dim numericStrings() As String = { "123456789", "+123456789", "pos 123456789", _
"-123456789", "neg 123456789", "123456789.", _
"123,456,789", "(123456789)", "2147483648", _
"-2147483649" }
' Use each provider to parse all the numeric strings.
For ctr As Integer = 0 To 1
Dim provider As IFormatPRovider = providers(ctr)
Console.WriteLine(IIf(ctr = 0, "Custom Provider:", "Invariant Provider:"))
For Each numericString As String In numericStrings
Console.Write("{0,15} --> ", numericString)
Try
Console.WriteLine("{0,20}", Convert.ToInt32(numericString, provider))
Catch e As FormatException
Console.WriteLine("{0,20}", "FormatException")
Catch e As OverflowException
Console.WriteLine("{0,20}", "OverflowException")
End Try
Next
Console.WriteLine()
Next
End Sub
End Module
' The example displays the following output:
' Custom Provider:
' 123456789 --> 123456789
' +123456789 --> FormatException
' pos 123456789 --> 123456789
' -123456789 --> FormatException
' neg 123456789 --> -123456789
' 123456789. --> FormatException
' 123,456,789 --> FormatException
' (123456789) --> FormatException
' 2147483648 --> OverflowException
' -2147483649 --> FormatException
'
' Invariant Provider:
' 123456789 --> 123456789
' +123456789 --> 123456789
' pos 123456789 --> FormatException
' -123456789 --> -123456789
' neg 123456789 --> FormatException
' 123456789. --> FormatException
' 123,456,789 --> FormatException
' (123456789) --> FormatException
' 2147483648 --> OverflowException
' -2147483649 --> OverflowException
注解
返回值是在 上value调用 Int32.Parse 方法的结果。
provider 是获取 IFormatProviderNumberFormatInfo 对象的实例。 对象 NumberFormatInfo 提供有关 格式的 value区域性特定信息。 如果 provider 为 null， NumberFormatInfo 则使用当前区域性的 。
如果不想在转换失败时处理异常，可以改为调用 Int32.TryParse 方法。 它返回一个 Boolean 值，该值指示转换是成功还是失败。
适用于
ToInt32(String, Int32)
- Source:
- Convert.cs
- Source:
- Convert.cs
- Source:
- Convert.cs
将指定基数的数字的字符串表示形式转换为等效的 32 位有符号整数。
public:
static int ToInt32(System::String ^ value, int fromBase);public static int ToInt32 (string value, int fromBase);public static int ToInt32 (string? value, int fromBase);static member ToInt32 : string * int -> intPublic Shared Function ToInt32 (value As String, fromBase As Integer) As Integer参数
- value
- String
包含要转换的数字的字符串。
- fromBase
- Int32
value 中数字的基数，它必须是 2、8、10 或 16。
返回
一个与 value 中数字等效的 32 位带符号整数，如果 value 为 null，则为 0（零）。
例外
value 为 Empty。
value 包含一个字符，该字符不是由 fromBase 指定的基数中的有效数字。 如果 value 中的第一个字符无效，则该异常消息指示没有要转换的数字；否则，该消息指示 value 包含无效的尾随字符。
注解
如果 fromBase 为 16，则可以在参数指定的 value 数字前面添加“0x”或“0X”。
由于非基数 10 数值表示形式不支持负号，因此 该方法 ToInt32(String, Int32) 假定负数使用二的补补表示形式。 换句话说，方法始终将整数的最高二进制位 (位 31) 解释为其符号位。 因此，可以编写代码，将数据类型范围 Int32 外的非基数 10 转换为 Int32 值，而不会引发方法异常。 以下示例递增 Int32.MaxValue 1，将生成的数字转换为其十六进制字符串表示形式，然后调用 ToInt32(String, Int32) 方法。 方法显示消息“0x80000000转换为 -2147483648”，而不是引发异常。
// Create a hexadecimal value out of range of the integer type.
String^ value1 = Convert::ToString((static_cast<__int64>(int::MaxValue)) + 1, 16);
// Convert it back to a number.
try {
int number = Convert::ToInt32(value1, 16);
Console::WriteLine("0x{0} converts to {1}.", value1, number);
}
catch (OverflowException ^e) {
Console::WriteLine("Unable to convert '0x{0}' to an integer.", value1);
}
// The example displays the following output:
// 0x80000000 converts to -2147483648.
// Create a hexadecimal value out of range of the Integer type.
string value = Convert.ToString((long) int.MaxValue + 1, 16);
// Convert it back to a number.
try
{
int number = Convert.ToInt32(value, 16);
Console.WriteLine("0x{0} converts to {1}.", value, number.ToString());
}
catch (OverflowException)
{
Console.WriteLine("Unable to convert '0x{0}' to an integer.", value);
}
// Create a hexadecimal value out of range of the Integer type.
let value = Convert.ToString(int64 Int32.MaxValue + 1L, 16)
// Convert it back to a number.
try
let number = Convert.ToInt32(value, 16)
printfn $"0x{value} converts to {number}."
with :? OverflowException ->
printfn $"Unable to convert '0x{value}' to an integer."
' Create a hexadecimal value out of range of the Integer type.
Dim value As String = Convert.ToString(CLng(Integer.MaxValue) + 1, 16)
' Convert it back to a number.
Try
Dim number As Integer = Convert.ToInt32(value, 16)
Console.WriteLine("0x{0} converts to {1}.", value, number)
Catch e As OverflowException
Console.WriteLine("Unable to convert '0x{0}' to an integer.", value)
End Try
在执行二进制运算或数值转换时，开发人员始终有责任验证方法是否使用适当的数值表示形式来解释特定值。 如以下示例所示，可以先检索数值的符号，然后再将其转换为其十六进制字符串表示形式，确保方法适当处理溢出。 如果原始值为正值，但转换回整数会生成负值，则引发异常。
__int64 sourceNumber2 = (static_cast<__int64>(int::MaxValue)) + 1;
bool isNegative = Math::Sign(sourceNumber2) == -1;
String^ value2 = Convert::ToString(sourceNumber2, 16);
int targetNumber;
try {
targetNumber = Convert::ToInt32(value2, 16);
if (!(isNegative) & (targetNumber & 0x80000000) != 0)
throw gcnew OverflowException();
else
Console::WriteLine("0x{0} converts to {1}.", value2, targetNumber);
}
catch (OverflowException ^e) {
Console::WriteLine("Unable to convert '0x{0}' to an integer.", value2);
}
// The example displays the following output:
// Unable to convert '0x80000000' to an integer.
// Create a hexadecimal value out of range of the Integer type.
long sourceNumber = (long) int.MaxValue + 1;
bool isNegative = Math.Sign(sourceNumber) == -1;
string value = Convert.ToString(sourceNumber, 16);
int targetNumber;
try
{
targetNumber = Convert.ToInt32(value, 16);
if (!(isNegative) & (targetNumber & 0x80000000) != 0)
throw new OverflowException();
else
Console.WriteLine("0x{0} converts to {1}.", value, targetNumber);
}
catch (OverflowException)
{
Console.WriteLine("Unable to convert '0x{0}' to an integer.", value);
}
// Displays the following to the console:
// Unable to convert '0x80000000' to an integer.
// Create a hexadecimal value out of range of the Integer type.
let sourceNumber = int64 Int32.MaxValue + 1L
let isNegative = sign sourceNumber = -1
let value = Convert.ToString(sourceNumber, 16)
try
let targetNumber = Convert.ToInt32(value, 16)
if not isNegative && targetNumber &&& 0x80000000 <> 0 then
raise (OverflowException())
else
printfn $"0x{value} converts to {targetNumber}."
with :? OverflowException ->
printfn $"Unable to convert '0x{value}' to an integer."
// Displays the following to the console:
// Unable to convert '0x80000000' to an integer.
' Create a hexadecimal value out of range of the Integer type.
Dim sourceNumber As Long = CLng(Integer.MaxValue) + 1
Dim isNegative As Boolean = (Math.Sign(sourceNumber) = -1)
Dim value As String = Convert.ToString(sourceNumber, 16)
Dim targetNumber As Integer
Try
targetNumber = Convert.ToInt32(value, 16)
If Not isNegative And ((targetNumber And &H80000000) <> 0) Then
Throw New OverflowException()
Else
Console.WriteLine("0x{0} converts to {1}.", value, targetNumber)
End If
Catch e As OverflowException
Console.WriteLine("Unable to convert '0x{0}' to an integer.", value)
End Try
' Displays the following to the console:
' Unable to convert '0x80000000' to an integer.
适用于
ToInt32(UInt64)
- Source:
- Convert.cs
- Source:
- Convert.cs
- Source:
- Convert.cs
重要
此 API 不符合 CLS。
将指定的 64 位无符号整数的值转换为等效的 32 位有符号整数。
public:
static int ToInt32(System::UInt64 value);[System.CLSCompliant(false)]
public static int ToInt32 (ulong value);[<System.CLSCompliant(false)>]
static member ToInt32 : uint64 -> intPublic Shared Function ToInt32 (value As ULong) As Integer参数
- value
- UInt64
要转换的 64 位无符号整数。
返回
一个与 value 等效的 32 位带符号整数。
- 属性
例外
value 大于 Int32.MaxValue。
示例
以下示例尝试将无符号长整数数组中的每个元素转换为有符号整数。
ulong[] numbers = { UInt64.MinValue, 121, 340, UInt64.MaxValue };
int result;
foreach (ulong number in numbers)
{
try {
result = Convert.ToInt32(number);
Console.WriteLine("Converted the {0} value {1} to a {2} value {3}.",
number.GetType().Name, number,
result.GetType().Name, result);
}
catch (OverflowException) {
Console.WriteLine("The {0} value {1} is outside the range of the Int32 type.",
number.GetType().Name, number);
}
}
// The example displays the following output:
// Converted the UInt64 value 0 to a Int32 value 0.
// Converted the UInt64 value 121 to a Int32 value 121.
// Converted the UInt64 value 340 to a Int32 value 340.
// The UInt64 value 18446744073709551615 is outside the range of the Int32 type.
let numbers =
[| UInt64.MinValue; 121uL; 340uL; UInt64.MaxValue |]
for number in numbers do
try
let result = Convert.ToInt32 number
printfn $"Converted the {number.GetType().Name} value {number} to the {result.GetType().Name} value {result}."
with :? OverflowException ->
printfn $"The {number.GetType().Name} value {number} is outside the range of the Int32 type."
// The example displays the following output:
// Converted the UInt64 value 0 to a Int32 value 0.
// Converted the UInt64 value 121 to a Int32 value 121.
// Converted the UInt64 value 340 to a Int32 value 340.
// The UInt64 value 18446744073709551615 is outside the range of the Int32 type.
Dim numbers() As ULong = { UInt64.MinValue, 121, 340, UInt64.MaxValue }
Dim result As Integer
For Each number As ULong In numbers
Try
result = Convert.ToInt32(number)
Console.WriteLine("Converted the {0} value {1} to a {2} value {3}.", _
number.GetType().Name, number, _
result.GetType().Name, result)
Catch e As OverflowException
Console.WriteLine("The {0} value {1} is outside the range of the Int32 type.", _
number.GetType().Name, number)
End Try
Next
' The example displays the following output:
' Converted the UInt64 value 0 to a Int32 value 0.
' Converted the UInt64 value 121 to a Int32 value 121.
' Converted the UInt64 value 340 to a Int32 value 340.
' The UInt64 value 18446744073709551615 is outside the range of the Int32 type.
适用于
ToInt32(SByte)
- Source:
- Convert.cs
- Source:
- Convert.cs
- Source:
- Convert.cs
重要
此 API 不符合 CLS。
将指定的 8 位带符号整数的值转换为等效的 32 位带符号整数。
public:
static int ToInt32(System::SByte value);[System.CLSCompliant(false)]
public static int ToInt32 (sbyte value);[<System.CLSCompliant(false)>]
static member ToInt32 : sbyte -> intPublic Shared Function ToInt32 (value As SByte) As Integer参数
- value
- SByte
要转换的 8 位带符号整数。
返回
一个与 value 等效的 8 位带符号整数。
- 属性
示例
以下示例将带符号字节数组中的每个元素转换为整数。
sbyte[] numbers = { SByte.MinValue, -1, 0, 10, SByte.MaxValue };
int result;
foreach (sbyte number in numbers)
{
result = Convert.ToInt32(number);
Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
number.GetType().Name, number,
result.GetType().Name, result);
}
// The example displays the following output:
// Converted the SByte value -128 to the Int32 value -128.
// Converted the SByte value -1 to the Int32 value -1.
// Converted the SByte value 0 to the Int32 value 0.
// Converted the SByte value 10 to the Int32 value 10.
// Converted the SByte value 127 to the Int32 value 127.
let numbers =
[| SByte.MinValue; -1y; 0y; 10y; SByte.MaxValue |]
for number in numbers do
let result = Convert.ToInt32 number
printfn $"Converted the {number.GetType().Name} value {number} to the {result.GetType().Name} value {result}."
// The example displays the following output:
// Converted the SByte value -128 to the Int32 value -128.
// Converted the SByte value -1 to the Int32 value -1.
// Converted the SByte value 0 to the Int32 value 0.
// Converted the SByte value 10 to the Int32 value 10.
// Converted the SByte value 127 to the Int32 value 127.
Dim numbers() As SByte = { SByte.MinValue, -1, 0, 10, SByte.MaxValue }
Dim result As Integer
For Each number As SByte In numbers
result = Convert.ToInt32(number)
Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
number.GetType().Name, number, _
result.GetType().Name, result)
Next
' The example displays the following output:
' Converted the SByte value -128 to the Int32 value -128.
' Converted the SByte value -1 to the Int32 value -1.
' Converted the SByte value 0 to the Int32 value 0.
' Converted the SByte value 10 to the Int32 value 10.
' Converted the SByte value 127 to the Int32 value 127.
适用于
ToInt32(Object)
- Source:
- Convert.cs
- Source:
- Convert.cs
- Source:
- Convert.cs
将指定对象的值转换为 32 位带符号整数。
public:
static int ToInt32(System::Object ^ value);public static int ToInt32 (object value);public static int ToInt32 (object? value);static member ToInt32 : obj -> intPublic Shared Function ToInt32 (value As Object) As Integer参数
- value
- Object
用于实现 IConvertible 接口的对象，或为 null。
返回
一个等效于 value 的 32 位带符号整数，如果 value 为 null，则为零。
例外
value 的格式不正确。
value 表示小于 Int32.MinValue 或大于 Int32.MaxValue 的数字。
示例
以下示例尝试将对象数组中的每个元素转换为整数。
object[] values = { true, -12, 163, 935, 'x', new DateTime(2009, 5, 12),
"104", "103.0", "-1",
"1.00e2", "One", 1.00e2, 16.3e42};
int result;
foreach (object value in values)
{
try {
result = Convert.ToInt32(value);
Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
value.GetType().Name, value,
result.GetType().Name, result);
}
catch (OverflowException) {
Console.WriteLine("The {0} value {1} is outside the range of the Int32 type.",
value.GetType().Name, value);
}
catch (FormatException) {
Console.WriteLine("The {0} value {1} is not in a recognizable format.",
value.GetType().Name, value);
}
catch (InvalidCastException) {
Console.WriteLine("No conversion to an Int32 exists for the {0} value {1}.",
value.GetType().Name, value);
}
}
// The example displays the following output:
// Converted the Boolean value True to the Int32 value 1.
// Converted the Int32 value -12 to the Int32 value -12.
// Converted the Int32 value 163 to the Int32 value 163.
// Converted the Int32 value 935 to the Int32 value 935.
// Converted the Char value x to the Int32 value 120.
// No conversion to an Int32 exists for the DateTime value 5/12/2009 12:00:00 AM.
// Converted the String value 104 to the Int32 value 104.
// The String value 103.0 is not in a recognizable format.
// Converted the String value -1 to the Int32 value -1.
// The String value 1.00e2 is not in a recognizable format.
// The String value One is not in a recognizable format.
// Converted the Double value 100 to the Int32 value 100.
// The Double value 1.63E+43 is outside the range of the Int32 type.
let values: obj[] =
[| true; -12; 163; 935; 'x'; DateTime(2009, 5, 12)
"104"; "103.0"; "-1"
"1.00e2"; "One"; 1.00e2; 16.3e42 |]
for value in values do
try
let result = Convert.ToInt32 value
printfn $"Converted the {value.GetType().Name} value {value} to the {result.GetType().Name} value {result}."
with
| :? OverflowException ->
printfn $"The {value.GetType().Name} value {value} is outside the range of the Int32 type."
| :? FormatException ->
printfn $"The {value.GetType().Name} value {value} is not in a recognizable format."
| :? InvalidCastException ->
printfn $"No conversion to an Int32 exists for the {value.GetType().Name} value {value}."
// The example displays the following output:
// Converted the Boolean value True to the Int32 value 1.
// Converted the Int32 value -12 to the Int32 value -12.
// Converted the Int32 value 163 to the Int32 value 163.
// Converted the Int32 value 935 to the Int32 value 935.
// Converted the Char value x to the Int32 value 120.
// No conversion to an Int32 exists for the DateTime value 5/12/2009 12:00:00 AM.
// Converted the String value 104 to the Int32 value 104.
// The String value 103.0 is not in a recognizable format.
// Converted the String value -1 to the Int32 value -1.
// The String value 1.00e2 is not in a recognizable format.
// The String value One is not in a recognizable format.
// Converted the Double value 100 to the Int32 value 100.
// The Double value 1.63E+43 is outside the range of the Int32 type.
Dim values() As Object = { True, -12, 163, 935, "x"c, #5/12/2009#, _
"104", "103.0", "-1", _
"1.00e2", "One", 1.00e2, 16.3e42}
Dim result As Integer
For Each value As Object In values
Try
result = Convert.ToInt32(value)
Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
value.GetType().Name, value, _
result.GetType().Name, result)
Catch e As OverflowException
Console.WriteLine("The {0} value {1} is outside the range of the Int32 type.", _
value.GetType().Name, value)
Catch e As FormatException
Console.WriteLine("The {0} value {1} is not in a recognizable format.", _
value.GetType().Name, value)
Catch e As InvalidCastException
Console.WriteLine("No conversion to an Int32 exists for the {0} value {1}.", _
value.GetType().Name, value)
End Try
Next
' The example displays the following output:
' Converted the Boolean value True to the Int32 value 1.
' Converted the Int32 value -12 to the Int32 value -12.
' Converted the Int32 value 163 to the Int32 value 163.
' Converted the Int32 value 935 to the Int32 value 935.
' Converted the Char value x to the Int32 value 120.
' No conversion to an Int32 exists for the DateTime value 5/12/2009 12:00:00 AM.
' Converted the String value 104 to the Int32 value 104.
' The String value 103.0 is not in a recognizable format.
' Converted the String value -1 to the Int32 value -1.
' The String value 1.00e2 is not in a recognizable format.
' The String value One is not in a recognizable format.
' Converted the Double value 100 to the Int32 value 100.
' The Double value 1.63E+43 is outside the range of the Int32 type.
注解
如果value 不是 null，则此方法包装对 IConvertible.ToInt32 基础类型的 实现的 value调用。
适用于
ToInt32(Int64)
- Source:
- Convert.cs
- Source:
- Convert.cs
- Source:
- Convert.cs
将指定的 64 位有符号整数的值转换为等效的 32 位有符号整数。
public:
static int ToInt32(long value);public static int ToInt32 (long value);static member ToInt32 : int64 -> intPublic Shared Function ToInt32 (value As Long) As Integer参数
- value
- Int64
要转换的 64 位带符号整数。
返回
一个与 value 等效的 32 位带符号整数。
例外
value 大于 Int32.MaxValue 或小于 Int32.MinValue。
示例
以下示例尝试将长整数数组中的每个元素转换为整数。
long[] numbers = { Int64.MinValue, -1, 0, 121, 340, Int64.MaxValue };
int result;
foreach (long number in numbers)
{
try {
result = Convert.ToInt32(number);
Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
number.GetType().Name, number,
result.GetType().Name, result);
}
catch (OverflowException) {
Console.WriteLine("The {0} value {1} is outside the range of the Int32 type.",
number.GetType().Name, number);
}
}
// The example displays the following output:
// The Int64 value -9223372036854775808 is outside the range of the Int32 type.
// Converted the Int64 value -1 to the Int32 value -1.
// Converted the Int64 value 0 to the Int32 value 0.
// Converted the Int64 value 121 to the Int32 value 121.
// Converted the Int64 value 340 to the Int32 value 340.
// The Int64 value 9223372036854775807 is outside the range of the Int32 type.
let numbers =
[| Int64.MinValue; -1; 0; 121; 340; Int64.MaxValue |]
for number in numbers do
try
let result = Convert.ToInt32 number
printfn $"Converted the {number.GetType().Name} value {number} to the {result.GetType().Name} value {result}."
with :? OverflowException ->
printfn $"The {number.GetType().Name} value {number} is outside the range of the Int32 type."
// The example displays the following output:
// The Int64 value -9223372036854775808 is outside the range of the Int32 type.
// Converted the Int64 value -1 to the Int32 value -1.
// Converted the Int64 value 0 to the Int32 value 0.
// Converted the Int64 value 121 to the Int32 value 121.
// Converted the Int64 value 340 to the Int32 value 340.
// The Int64 value 9223372036854775807 is outside the range of the Int32 type.
Dim numbers() As Long = { Int64.MinValue, -1, 0, 121, 340, Int64.MaxValue }
Dim result As Integer
For Each number As Long In numbers
Try
result = Convert.ToInt32(number)
Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
number.GetType().Name, number, _
result.GetType().Name, result)
Catch e As OverflowException
Console.WriteLine("The {0} value {1} is outside the range of the Int32 type.", _
number.GetType().Name, number)
End Try
Next
' The example displays the following output:
' The Int64 value -9223372036854775808 is outside the range of the Int32 type.
' Converted the Int64 value -1 to the Int32 value -1.
' Converted the Int64 value 0 to the Int32 value 0.
' Converted the Int64 value 121 to the Int32 value 121.
' Converted the Int64 value 340 to the Int32 value 340.
' The Int64 value 9223372036854775807 is outside the range of the Int32 type.
适用于
ToInt32(Byte)
- Source:
- Convert.cs
- Source:
- Convert.cs
- Source:
- Convert.cs
将指定的 8 位无符号整数的值转换为等效的 32 位有符号整数。
public:
static int ToInt32(System::Byte value);public static int ToInt32 (byte value);static member ToInt32 : byte -> intPublic Shared Function ToInt32 (value As Byte) As Integer参数
- value
- Byte
要转换的 8 位无符号整数。
返回
一个与 value 等效的 32 位带符号整数。
示例
以下示例将字节数组中的每个元素转换为整数。
byte[] bytes = { Byte.MinValue, 14, 122, Byte.MaxValue};
int result;
foreach (byte byteValue in bytes)
{
result = Convert.ToInt32(byteValue);
Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
byteValue.GetType().Name, byteValue,
result.GetType().Name, result);
}
// The example displays the following output:
// Converted the Byte value 0 to the Int32 value 0.
// Converted the Byte value 14 to the Int32 value 14.
// Converted the Byte value 122 to the Int32 value 122.
// Converted the Byte value 255 to the Int32 value 255.
let bytes =
[| Byte.MinValue; 14uy; 122uy; Byte.MaxValue |]
for byteValue in bytes do
let result = Convert.ToInt32 byteValue
printfn $"Converted the {byteValue.GetType().Name} value {byteValue} to the {result.GetType().Name} value {result}."
// The example displays the following output:
// Converted the Byte value 0 to the Int32 value 0.
// Converted the Byte value 14 to the Int32 value 14.
// Converted the Byte value 122 to the Int32 value 122.
// Converted the Byte value 255 to the Int32 value 255.
Dim bytes() As Byte = { Byte.MinValue, 14, 122, Byte.MaxValue}
Dim result As Integer
For Each byteValue As Byte In bytes
result = Convert.ToInt32(byteValue)
Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
byteValue.GetType().Name, byteValue, _
result.GetType().Name, result)
Next
' The example displays the following output:
' Converted the Byte value 0 to the Int32 value 0.
' Converted the Byte value 14 to the Int32 value 14.
' Converted the Byte value 122 to the Int32 value 122.
' Converted the Byte value 255 to the Int32 value 255.
适用于
ToInt32(Char)
- Source:
- Convert.cs
- Source:
- Convert.cs
- Source:
- Convert.cs
将指定的 Unicode 字符的值转换为等效的 32 位有符号整数。
public:
static int ToInt32(char value);public static int ToInt32 (char value);static member ToInt32 : char -> intPublic Shared Function ToInt32 (value As Char) As Integer参数
- value
- Char
要转换的 Unicode 字符。
返回
一个与 value 等效的 32 位带符号整数。
示例
以下示例将值数组 Char 中的每个元素转换为整数。
char[] chars = { 'a', 'z', '\u0007', '\u03FF',
'\u7FFF', '\uFFFE' };
int result;
foreach (char ch in chars)
{
try {
result = Convert.ToInt32(ch);
Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.",
ch.GetType().Name, ch,
result.GetType().Name, result);
}
catch (OverflowException) {
Console.WriteLine("Unable to convert u+{0} to an Int32.",
((int)ch).ToString("X4"));
}
}
// The example displays the following output:
// Converted the Char value 'a' to the Int32 value 97.
// Converted the Char value 'z' to the Int32 value 122.
// Converted the Char value '' to the Int32 value 7.
// Converted the Char value 'Ͽ' to the Int32 value 1023.
// Converted the Char value '翿' to the Int32 value 32767.
// Converted the Char value '' to the Int32 value 65534.
let chars =
[| 'a'; 'z'; '\u0007'; '\u03FF'; '\u7FFF'; '\uFFFE' |]
for ch in chars do
try
let result = Convert.ToInt32 ch
printfn $"Converted the {ch.GetType().Name} value '{ch}' to the {result.GetType().Name} value {result}."
with :? OverflowException ->
printfn $"Unable to convert u+{int ch:X4} to an Int32."
// The example displays the following output:
// Converted the Char value 'a' to the Int32 value 97.
// Converted the Char value 'z' to the Int32 value 122.
// Converted the Char value '' to the Int32 value 7.
// Converted the Char value 'Ͽ' to the Int32 value 1023.
// Converted the Char value '翿' to the Int32 value 32767.
// Converted the Char value '' to the Int32 value 65534.
Dim chars() As Char = { "a"c, "z"c, ChrW(7), ChrW(1023), _
ChrW(Short.MaxValue), ChrW(&hFFFE) }
Dim result As Integer
For Each ch As Char in chars
Try
result = Convert.ToInt32(ch)
Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _
ch.GetType().Name, ch, _
result.GetType().Name, result)
Catch e As OverflowException
Console.WriteLine("Unable to convert u+{0} to an Int32.", _
AscW(ch).ToString("X4"))
End Try
Next
' The example displays the following output:
' Converted the Char value 'a' to the Int32 value 97.
' Converted the Char value 'z' to the Int32 value 122.
' Converted the Char value '' to the Int32 value 7.
' Converted the Char value 'Ͽ' to the Int32 value 1023.
' Converted the Char value '翿' to the Int32 value 32767.
' Converted the Char value '' to the Int32 value 65534.
注解
方法 ToInt32(Char) 返回一个 32 位带符号整数，该整数表示参数的 value UTF-16 编码代码单元。 如果 value 不是低代理项或高代理项，则此返回值还表示值的 Unicode 代码点。
适用于
ToInt32(DateTime)
- Source:
- Convert.cs
- Source:
- Convert.cs
- Source:
- Convert.cs
调用此方法始终引发 InvalidCastException。
public:
static int ToInt32(DateTime value);public static int ToInt32 (DateTime value);static member ToInt32 : DateTime -> intPublic Shared Function ToInt32 (value As DateTime) As Integer参数
- value
- DateTime
要转换的日期和时间值。
返回
不支持此转换。 不返回任何值。
例外
不支持此转换。
适用于
ToInt32(Boolean)
- Source:
- Convert.cs
- Source:
- Convert.cs
- Source:
- Convert.cs
将指定的布尔值转换为等效的 32 位带符号整数。
public:
static int ToInt32(bool value);public static int ToInt32 (bool value);static member ToInt32 : bool -> intPublic Shared Function ToInt32 (value As Boolean) As Integer参数
- value
- Boolean
要转换的布尔值。
返回
如果 value 为 true，则为数字 1；否则，为 0。
示例
以下示例将 Boolean 值 true 和 false 转换为整数。
bool falseFlag = false;
bool trueFlag = true;
Console.WriteLine("{0} converts to {1}.", falseFlag,
Convert.ToInt32(falseFlag));
Console.WriteLine("{0} converts to {1}.", trueFlag,
Convert.ToInt32(trueFlag));
// The example displays the following output:
// False converts to 0.
// True converts to 1.
let falseFlag = false
let trueFlag = true
printfn $"{falseFlag} converts to {Convert.ToInt32 falseFlag}."
printfn $"{trueFlag} converts to {Convert.ToInt32 trueFlag}."
// The example displays the following output:
// False converts to 0.
// True converts to 1.
Dim falseFlag As Boolean = False
Dim trueFlag As Boolean = True
Console.WriteLine("{0} converts to {1}.", falseFlag, _
Convert.ToInt32(falseFlag))
Console.WriteLine("{0} converts to {1}.", trueFlag, _
Convert.ToInt32(trueFlag))
' The example displays the following output:
' False converts to 0.
' True converts to 1.
适用于
ToInt32(Double)
- Source:
- Convert.cs
- Source:
- Convert.cs
- Source:
- Convert.cs
将指定的双精度浮点数的值转换为等效的 32 位带符号整数。
public:
static int ToInt32(double value);public static int ToInt32 (double value);static member ToInt32 : double -> intPublic Shared Function ToInt32 (value As Double) As Integer参数
- value
- Double
要转换的双精度浮点数。
返回
value，舍入为最接近的 32 位有符号整数。 如果 value 为两个整数中间的数字，则返回二者中的偶数；即 4.5 转换为 4，而 5.5 转换为 6。
例外
value 大于 Int32.MaxValue 或小于 Int32.MinValue。
示例
以下示例尝试将值数组 Double 中的每个元素转换为整数。
double[] values= { Double.MinValue, -1.38e10, -1023.299, -12.98,
0, 9.113e-16, 103.919, 17834.191, Double.MaxValue };
int result;
foreach (double value in values)
{
try {
result = Convert.ToInt32(value);
Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.",
value.GetType().Name, value,
result.GetType().Name, result);
}
catch (OverflowException) {
Console.WriteLine("{0} is outside the range of the Int32 type.", value);
}
}
// -1.79769313486232E+308 is outside the range of the Int32 type.
// -13800000000 is outside the range of the Int32 type.
// Converted the Double value '-1023.299' to the Int32 value -1023.
// Converted the Double value '-12.98' to the Int32 value -13.
// Converted the Double value '0' to the Int32 value 0.
// Converted the Double value '9.113E-16' to the Int32 value 0.
// Converted the Double value '103.919' to the Int32 value 104.
// Converted the Double value '17834.191' to the Int32 value 17834.
// 1.79769313486232E+308 is outside the range of the Int32 type.
let values =
[| Double.MinValue; -1.38e10; -1023.299; -12.98
0; 9.113e-16; 103.919; 17834.191; Double.MaxValue |]
for value in values do
try
let result = Convert.ToInt32 value
printfn $"Converted the {value.GetType().Name} value '{value}' to the {result.GetType().Name} value {result}."
with :? OverflowException ->
printfn $"{value} is outside the range of the Int32 type."
// -1.79769313486232E+308 is outside the range of the Int32 type.
// -13800000000 is outside the range of the Int32 type.
// Converted the Double value '-1023.299' to the Int32 value -1023.
// Converted the Double value '-12.98' to the Int32 value -13.
// Converted the Double value '0' to the Int32 value 0.
// Converted the Double value '9.113E-16' to the Int32 value 0.
// Converted the Double value '103.919' to the Int32 value 104.
// Converted the Double value '17834.191' to the Int32 value 17834.
// 1.79769313486232E+308 is outside the range of the Int32 type.
Dim values() As Double = { Double.MinValue, -1.38e10, -1023.299, -12.98, _
0, 9.113e-16, 103.919, 17834.191, Double.MaxValue }
Dim result As Integer
For Each value As Double In values
Try
result = Convert.ToInt32(value)
Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _
value.GetType().Name, value, _
result.GetType().Name, result)
Catch e As OverflowException
Console.WriteLine("{0} is outside the range of the Int32 type.", value)
End Try
Next
' -1.79769313486232E+308 is outside the range of the Int32 type.
' -13800000000 is outside the range of the Int32 type.
' Converted the Double value '-1023.299' to the Int32 value -1023.
' Converted the Double value '-12.98' to the Int32 value -13.
' Converted the Double value '0' to the Int32 value 0.
' Converted the Double value '9.113E-16' to the Int32 value 0.
' Converted the Double value '103.919' to the Int32 value 104.
' Converted the Double value '17834.191' to the Int32 value 17834.
' 1.79769313486232E+308 is outside the range of the Int32 type.
另请参阅
适用于
ToInt32(Int16)
- Source:
- Convert.cs
- Source:
- Convert.cs
- Source:
- Convert.cs
将指定的 16 位有符号整数的值转换为等效的 32 位有符号整数。
public:
static int ToInt32(short value);public static int ToInt32 (short value);static member ToInt32 : int16 -> intPublic Shared Function ToInt32 (value As Short) As Integer参数
- value
- Int16
要转换的 16 位带符号整数。
返回
一个与 value 等效的 32 位带符号整数。
示例
以下示例将 16 位带符号整数数组中的每个元素转换为整数。
short[] numbers= { Int16.MinValue, -1, 0, 121, 340, Int16.MaxValue };
int result;
foreach (short number in numbers)
{
result = Convert.ToInt32(number);
Console.WriteLine("Converted the {0} value {1} to a {2} value {3}.",
number.GetType().Name, number,
result.GetType().Name, result);
}
// The example displays the following output:
// Converted the Int16 value -32768 to a Int32 value -32768.
// Converted the Int16 value -1 to a Int32 value -1.
// Converted the Int16 value 0 to a Int32 value 0.
// Converted the Int16 value 121 to a Int32 value 121.
// Converted the Int16 value 340 to a Int32 value 340.
// Converted the Int16 value 32767 to a Int32 value 32767.
let numbers =
[| Int16.MinValue; -1s; 0s; 121s; 340s; Int16.MaxValue |]
for number in numbers do
let result = Convert.ToInt32 number
printfn $"Converted the {number.GetType().Name} value {number} to a {result.GetType().Name} value {result}."
// The example displays the following output:
// Converted the Int16 value -32768 to a Int32 value -32768.
// Converted the Int16 value -1 to a Int32 value -1.
// Converted the Int16 value 0 to a Int32 value 0.
// Converted the Int16 value 121 to a Int32 value 121.
// Converted the Int16 value 340 to a Int32 value 340.
// Converted the Int16 value 32767 to a Int32 value 32767.
Dim numbers() As Short = { Int16.MinValue, -1, 0, 121, 340, Int16.MaxValue }
Dim result As Integer
For Each number As Short In numbers
result = Convert.ToInt32(number)
Console.WriteLine("Converted the {0} value {1} to a {2} value {3}.", _
number.GetType().Name, number, _
result.GetType().Name, result)
Next
' The example displays the following output:
' Converted the Int16 value -32768 to a Int32 value -32768.
' Converted the Int16 value -1 to a Int32 value -1.
' Converted the Int16 value 0 to a Int32 value 0.
' Converted the Int16 value 121 to a Int32 value 121.
' Converted the Int16 value 340 to a Int32 value 340.
' Converted the Int16 value 32767 to a Int32 value 32767.
适用于
ToInt32(Int32)
- Source:
- Convert.cs
- Source:
- Convert.cs
- Source:
- Convert.cs
返回指定的 32 位有符号整数；不执行实际的转换。
public:
static int ToInt32(int value);public static int ToInt32 (int value);static member ToInt32 : int -> intPublic Shared Function ToInt32 (value As Integer) As Integer参数
- value
- Int32
要转换的 32 位无符号整数。
返回
不经更改即返回 value。
适用于
ToInt32(Decimal)
- Source:
- Convert.cs
- Source:
- Convert.cs
- Source:
- Convert.cs
将指定的十进制数的值转换为等效的 32 位带符号整数。
public:
static int ToInt32(System::Decimal value);public static int ToInt32 (decimal value);static member ToInt32 : decimal -> intPublic Shared Function ToInt32 (value As Decimal) As Integer参数
- value
- Decimal
要转换的十进制数。
返回
value，舍入为最接近的 32 位有符号整数。 如果 value 为两个整数中间的数字，则返回二者中的偶数；即 4.5 转换为 4，而 5.5 转换为 6。
例外
value 大于 Int32.MaxValue 或小于 Int32.MinValue。
示例
以下示例尝试将值数组 Decimal 中的每个元素转换为整数。
decimal[] values= { Decimal.MinValue, -1034.23m, -12m, 0m, 147m,
199.55m, 9214.16m, Decimal.MaxValue };
int result;
foreach (decimal value in values)
{
try {
result = Convert.ToInt32(value);
Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.",
value.GetType().Name, value,
result.GetType().Name, result);
}
catch (OverflowException) {
Console.WriteLine("{0} is outside the range of the Int32 type.",
value);
}
}
// The example displays the following output:
// -79228162514264337593543950335 is outside the range of the Int32 type.
// Converted the Decimal value '-1034.23' to the Int32 value -1034.
// Converted the Decimal value '-12' to the Int32 value -12.
// Converted the Decimal value '0' to the Int32 value 0.
// Converted the Decimal value '147' to the Int32 value 147.
// Converted the Decimal value '199.55' to the Int32 value 200.
// Converted the Decimal value '9214.16' to the Int32 value 9214.
// 79228162514264337593543950335 is outside the range of the Int32 type.
let values =
[| Decimal.MinValue; -1034.23m; -12m; 0m; 147m
199.55m; 9214.16m; Decimal.MaxValue |]
for value in values do
try
let result = Convert.ToInt32 value
printfn $"Converted the {value.GetType().Name} value '{value}' to the {result.GetType().Name} value {result}."
with :? OverflowException ->
printfn $"{value} is outside the range of the Int32 type."
// The example displays the following output:
// -79228162514264337593543950335 is outside the range of the Int32 type.
// Converted the Decimal value '-1034.23' to the Int32 value -1034.
// Converted the Decimal value '-12' to the Int32 value -12.
// Converted the Decimal value '0' to the Int32 value 0.
// Converted the Decimal value '147' to the Int32 value 147.
// Converted the Decimal value '199.55' to the Int32 value 200.
// Converted the Decimal value '9214.16' to the Int32 value 9214.
// 79228162514264337593543950335 is outside the range of the Int32 type.
Dim values() As Decimal = { Decimal.MinValue, -1034.23d, -12d, 0d, 147d, _
199.55d, 9214.16d, Decimal.MaxValue }
Dim result As Integer
For Each value As Decimal In values
Try
result = Convert.ToInt32(value)
Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _
value.GetType().Name, value, _
result.GetType().Name, result)
Catch e As OverflowException
Console.WriteLine("{0} is outside the range of the Int32 type.", _
value)
End Try
Next
' The example displays the following output:
' -79228162514264337593543950335 is outside the range of the Int32 type.
' Converted the Decimal value '-1034.23' to the Int32 value -1034.
' Converted the Decimal value '-12' to the Int32 value -12.
' Converted the Decimal value '0' to the Int32 value 0.
' Converted the Decimal value '147' to the Int32 value 147.
' Converted the Decimal value '199.55' to the Int32 value 200.
' Converted the Decimal value '9214.16' to the Int32 value 9214.
' 79228162514264337593543950335 is outside the range of the Int32 type.
