Convert.ToChar Metodo
Definizione
Importante
Alcune informazioni sono relative alla release non definitiva del prodotto, che potrebbe subire modifiche significative prima della release definitiva. Microsoft non riconosce alcuna garanzia, espressa o implicita, in merito alle informazioni qui fornite.
Converte un valore specificato in un carattere Unicode.
Overload
| ToChar(String, IFormatProvider) |
Converte il primo carattere di una stringa specificata in un carattere Unicode mediante le informazioni di formattazione specifiche delle impostazioni cultura indicate. |
| ToChar(Object) |
Converte il valore dell'oggetto specificato in un carattere Unicode. |
| ToChar(Object, IFormatProvider) |
Converte il valore dell'oggetto specificato nel relativo carattere Unicode equivalente mediante le informazioni di formattazione specifiche delle impostazioni cultura indicate. |
| ToChar(UInt64) |
Converte il valore dell'intero senza segno a 64 bit specificato nel carattere Unicode equivalente. |
| ToChar(UInt32) |
Converte il valore dell'intero senza segno a 32 bit specificato nel carattere Unicode equivalente. |
| ToChar(UInt16) |
Converte il valore dell'intero senza segno a 16 bit specificato nel carattere Unicode equivalente. |
| ToChar(String) |
Converte il primo carattere di una stringa specificata in un carattere Unicode. |
| ToChar(Single) |
La chiamata di questo metodo genera sempre un'eccezione InvalidCastException. |
| ToChar(SByte) |
Converte il valore dell'intero con segno a 8 bit specificato nel carattere Unicode equivalente. |
| ToChar(Int64) |
Converte il valore dell'intero con segno a 64 bit specificato nel carattere Unicode equivalente. |
| ToChar(Int16) |
Converte il valore dell'intero con segno a 16 bit specificato nel carattere Unicode equivalente. |
| ToChar(Double) |
La chiamata di questo metodo genera sempre un'eccezione InvalidCastException. |
| ToChar(Decimal) |
La chiamata di questo metodo genera sempre un'eccezione InvalidCastException. |
| ToChar(DateTime) |
La chiamata di questo metodo genera sempre un'eccezione InvalidCastException. |
| ToChar(Char) |
Restituisce il valore del carattere Unicode specificato; non viene eseguita alcuna conversione effettiva. |
| ToChar(Byte) |
Converte il valore dell'intero senza segno a 8 bit specificato nel carattere Unicode equivalente. |
| ToChar(Boolean) |
La chiamata di questo metodo genera sempre un'eccezione InvalidCastException. |
| ToChar(Int32) |
Converte il valore dell'intero con segno a 32 bit specificato nel carattere Unicode equivalente. |
ToChar(String, IFormatProvider)
- Origine:
- Convert.cs
- Origine:
- Convert.cs
- Origine:
- Convert.cs
Converte il primo carattere di una stringa specificata in un carattere Unicode mediante le informazioni di formattazione specifiche delle impostazioni cultura indicate.
public:
static char ToChar(System::String ^ value, IFormatProvider ^ provider);public static char ToChar (string value, IFormatProvider provider);public static char ToChar (string value, IFormatProvider? provider);static member ToChar : string * IFormatProvider -> charPublic Shared Function ToChar (value As String, provider As IFormatProvider) As CharParametri
- value
- String
Stringa di lunghezza 1 oppure null.
- provider
- IFormatProvider
Oggetto che fornisce informazioni di formattazione specifiche delle impostazioni cultura. Questo parametro viene ignorato.
Restituisce
Carattere Unicode equivalente al primo e unico carattere in value.
Eccezioni
value è null.
La lunghezza di value non è 1.
Esempio
L'esempio seguente converte una rappresentazione stringa di un Char valore con il ToChar metodo, usando un IFormatProvider oggetto che visualizza il tipo del provider di formato per cui viene chiamato. L'esempio mostra che il provider di formato non viene fatto riferimento.
using namespace System;
using namespace System::Globalization;
ref class DummyProvider: public IFormatProvider
{
public:
// Normally, GetFormat returns an object of the requested type
// (usually itself) if it is able; otherwise, it returns Nothing.
virtual Object^ GetFormat( Type^ argType )
{
// Here, GetFormat displays the name of argType, after removing
// the namespace information. GetFormat always returns null.
String^ argStr = argType->ToString();
if ( argStr->Equals( "" ) )
argStr = "Empty";
argStr = argStr->Substring( argStr->LastIndexOf( '.' ) + 1 );
Console::Write( "{0,-20}", argStr );
return (Object^)0;
}
};
int main()
{
// Create an instance of IFormatProvider.
DummyProvider^ provider = gcnew DummyProvider;
String^ format = "{0,-17}{1,-17}{2}";
// Convert these values using DummyProvider.
String^ Int32A = "-252645135";
String^ DoubleA = "61680.3855";
String^ DayTimeA = "2001/9/11 13:45";
String^ BoolA = "True";
String^ StringA = "Qwerty";
String^ CharA = "$";
Console::WriteLine( "This example of selected "
"Convert::To<Type>( String*, IFormatProvider* ) \nmethods "
"generates the following output. The example displays the "
"\nprovider type if the IFormatProvider is called." );
Console::WriteLine( "\nNote: For the "
"ToBoolean, ToString, and ToChar methods, the \n"
"IFormatProvider object is not referenced." );
// The format provider is called for the following conversions.
Console::WriteLine();
Console::WriteLine( format, "ToInt32", Int32A, Convert::ToInt32( Int32A, provider ) );
Console::WriteLine( format, "ToDouble", DoubleA, Convert::ToDouble( DoubleA, provider ) );
Console::WriteLine( format, "ToDateTime", DayTimeA, Convert::ToDateTime( DayTimeA, provider ) );
// The format provider is not called for these conversions.
Console::WriteLine();
Console::WriteLine( format, "ToBoolean", BoolA, Convert::ToBoolean( BoolA, provider ) );
Console::WriteLine( format, "ToString", StringA, Convert::ToString( StringA, provider ) );
Console::WriteLine( format, "ToChar", CharA, Convert::ToChar( CharA, provider ) );
}
/*
This example of selected Convert::To<Type>( String*, IFormatProvider* )
methods generates the following output. The example displays the
provider type if the IFormatProvider is called.
Note: For the ToBoolean, ToString, and ToChar methods, the
IFormatProvider object is not referenced.
NumberFormatInfo ToInt32 -252645135 -252645135
NumberFormatInfo ToDouble 61680.3855 61680.3855
DateTimeFormatInfo ToDateTime 2001/9/11 13:45 9/11/2001 1:45:00 PM
ToBoolean True True
ToString Qwerty Qwerty
ToChar $ $
*/
using System;
using System.Globalization;
public class DummyProvider : IFormatProvider
{
// Normally, GetFormat returns an object of the requested type
// (usually itself) if it is able; otherwise, it returns Nothing.
public object GetFormat(Type argType)
{
// Here, GetFormat displays the name of argType, after removing
// the namespace information. GetFormat always returns null.
string argStr = argType.ToString( );
if( argStr == "" )
argStr = "Empty";
argStr = argStr.Substring( argStr.LastIndexOf( '.' ) + 1 );
Console.Write( "{0,-20}", argStr );
return null;
}
}
class ConvertNonNumericProviderDemo
{
public static void Main( )
{
// Create an instance of IFormatProvider.
DummyProvider provider = new DummyProvider( );
string format = "{0,-17}{1,-17}{2}";
// Convert these values using DummyProvider.
string Int32A = "-252645135";
string DoubleA = "61680.3855";
string DayTimeA = "2001/9/11 13:45";
string BoolA = "True";
string StringA = "Qwerty";
string CharA = "$";
Console.WriteLine( "This example of selected " +
"Convert.To<Type>( String, IFormatProvider ) \nmethods " +
"generates the following output. The example displays " +
"the \nprovider type if the IFormatProvider is called." );
Console.WriteLine( "\nNote: For the " +
"ToBoolean, ToString, and ToChar methods, the \n" +
"IFormatProvider object is not referenced." );
// The format provider is called for the following conversions.
Console.WriteLine( );
Console.WriteLine( format, "ToInt32", Int32A,
Convert.ToInt32( Int32A, provider ) );
Console.WriteLine( format, "ToDouble", DoubleA,
Convert.ToDouble( DoubleA, provider ) );
Console.WriteLine( format, "ToDateTime", DayTimeA,
Convert.ToDateTime( DayTimeA, provider ) );
// The format provider is not called for these conversions.
Console.WriteLine( );
Console.WriteLine( format, "ToBoolean", BoolA,
Convert.ToBoolean( BoolA, provider ) );
Console.WriteLine( format, "ToString", StringA,
Convert.ToString( StringA, provider ) );
Console.WriteLine( format, "ToChar", CharA,
Convert.ToChar( CharA, provider ) );
}
}
/*
This example of selected Convert.To<Type>( String, IFormatProvider )
methods generates the following output. The example displays the
provider type if the IFormatProvider is called.
Note: For the ToBoolean, ToString, and ToChar methods, the
IFormatProvider object is not referenced.
NumberFormatInfo ToInt32 -252645135 -252645135
NumberFormatInfo ToDouble 61680.3855 61680.3855
DateTimeFormatInfo ToDateTime 2001/9/11 13:45 9/11/2001 1:45:00 PM
ToBoolean True True
ToString Qwerty Qwerty
ToChar $ $
*/
open System
open System.Globalization
type DummyProvider() =
interface IFormatProvider with
// Normally, GetFormat returns an object of the requested type
// (usually itself) if it is able; otherwise, it returns Nothing.
member _.GetFormat(argType: Type) =
// Here, GetFormat displays the name of argType, after removing
// the namespace information. GetFormat always returns null.
let argStr = string argType
let argStr = if argStr = "" then "Empty" else argStr
let argStr = argStr.Substring(argStr.LastIndexOf '.' + 1)
printf $"{argStr,-20}"
null
// Create an instance of IFormatProvider.
let provider =
{ new IFormatProvider with
// Normally, GetFormat returns an object of the requested type
// (usually itself) if it is able; otherwise, it returns Nothing.
member _.GetFormat(argType: Type) =
// Here, GetFormat displays the name of argType, after removing
// the namespace information. GetFormat always returns null.
let argStr = string argType
let argStr = if argStr = "" then "Empty" else argStr
let argStr = argStr.Substring(argStr.LastIndexOf '.' + 1)
printf $"{argStr,-20}"
null }
let format obj1 obj2 obj3 = printfn $"{obj1,-17}{obj2,-17}{obj3}"
// Convert these values using DummyProvider.
let Int32A = "-252645135"
let DoubleA = "61680.3855"
let DayTimeA = "2001/9/11 13:45"
let BoolA = "True"
let StringA = "Qwerty"
let CharA = "$"
printfn
"""This example of selected Convert.To<Type>( String, IFormatProvider )
methods generates the following output. The example displays the
provider type if the IFormatProvider is called.
Note: For the ToBoolean, ToString, and ToChar methods, the
IFormatProvider object is not referenced.
"""
// The format provider is called for the following conversions.
format "ToInt32" Int32A (Convert.ToInt32(Int32A, provider) )
format "ToDouble" DoubleA (Convert.ToDouble(DoubleA, provider) )
format "ToDateTime" DayTimeA (Convert.ToDateTime(DayTimeA, provider) )
// The format provider is not called for these conversions.
printfn ""
format "ToBoolean" BoolA (Convert.ToBoolean(BoolA, provider) )
format "ToString" StringA (Convert.ToString(StringA, provider) )
format "ToChar" CharA (Convert.ToChar(CharA, provider) )
// This example of selected Convert.To<Type>( String, IFormatProvider )
// methods generates the following output. The example displays the
// provider type if the IFormatProvider is called.
//
// Note: For the ToBoolean, ToString, and ToChar methods, the
// IFormatProvider object is not referenced.
//
// NumberFormatInfo ToInt32 -252645135 -252645135
// NumberFormatInfo ToDouble 61680.3855 61680.3855
// DateTimeFormatInfo ToDateTime 2001/9/11 13:45 9/11/2001 1:45:00 PM
//
// ToBoolean True True
// ToString Qwerty Qwerty
// ToChar $ $
Imports System.Globalization
Public Class DummyProvider
Implements IFormatProvider
' Normally, GetFormat returns an object of the requested type
' (usually itself) if it is able; otherwise, it returns Nothing.
Public Function GetFormat( argType As Type ) As Object _
Implements IFormatProvider.GetFormat
' Here, GetFormat displays the name of argType, after removing
' the namespace information. GetFormat always returns Nothing.
Dim argStr As String = argType.ToString( )
If argStr = "" Then argStr = "Empty"
argStr = argStr.Substring( argStr.LastIndexOf( "."c ) + 1 )
Console.Write( "{0,-20}", argStr )
Return Nothing
End Function
End Class
Module ConvertNonNumericProviderDemo
Sub Main( )
' Create an instance of IFormatProvider.
Dim provider As New DummyProvider( )
Dim format As String = "{0,-17}{1,-17}{2}"
' Convert these values using DummyProvider.
Dim Int32A As String = "-252645135"
Dim DoubleA As String = "61680.3855"
Dim DayTimeA As String = "2001/9/11 13:45"
Dim BoolA As String = "True"
Dim StringA As String = "Qwerty"
Dim CharA As String = "$"
Console.WriteLine( "This example of selected " & _
"Convert.To<Type>( String, IFormatProvider ) " & vbCrLf & _
"methods generates the following output. The example " & _
"displays the " & vbCrLf & "provider type if the " & _
"IFormatProvider is called." )
Console.WriteLine( vbCrLf & _
"Note: For the ToBoolean, ToString, and ToChar " & _
"methods, the " & vbCrLf & "IFormatProvider object " & _
"is not referenced." )
' The format provider is called for the following conversions.
Console.WriteLine( )
Console.WriteLine( format, "ToInt32", Int32A, _
Convert.ToInt32( Int32A, provider ) )
Console.WriteLine( format, "ToDouble", DoubleA, _
Convert.ToDouble( DoubleA, provider ) )
Console.WriteLine( format, "ToDateTime", DayTimeA, _
Convert.ToDateTime( DayTimeA, provider ) )
' The format provider is not called for these conversions.
Console.WriteLine( )
Console.WriteLine( format, "ToBoolean", BoolA, _
Convert.ToBoolean( BoolA, provider ) )
Console.WriteLine( format, "ToString", StringA, _
Convert.ToString( StringA, provider ) )
Console.WriteLine( format, "ToChar", CharA, _
Convert.ToChar( CharA, provider ) )
End Sub
End Module
' This example of selected Convert.To<Type>( String, IFormatProvider )
' methods generates the following output. The example displays the
' provider type if the IFormatProvider is called.
'
' Note: For the ToBoolean, ToString, and ToChar methods, the
' IFormatProvider object is not referenced.
'
' NumberFormatInfo ToInt32 -252645135 -252645135
' NumberFormatInfo ToDouble 61680.3855 61680.3855
' DateTimeFormatInfo ToDateTime 2001/9/11 13:45 9/11/2001 1:45:00 PM
'
' ToBoolean True True
' ToString Qwerty Qwerty
' ToChar $ $
Commenti
value deve essere una stringa contenente un singolo carattere.
Se si preferisce non gestire un'eccezione se la conversione ha esito negativo, è possibile chiamare invece il Char.TryParse metodo. Restituisce un Boolean valore che indica se la conversione ha avuto esito positivo o negativo.
Si applica a
ToChar(Object)
- Origine:
- Convert.cs
- Origine:
- Convert.cs
- Origine:
- Convert.cs
Converte il valore dell'oggetto specificato in un carattere Unicode.
public:
static char ToChar(System::Object ^ value);public static char ToChar (object value);public static char ToChar (object? value);static member ToChar : obj -> charPublic Shared Function ToChar (value As Object) As CharParametri
- value
- Object
Oggetto che implementa l'interfaccia IConvertible.
Restituisce
Carattere Unicode equivalente al valore o Char.MinValue se value è null.
Eccezioni
value è una stringa Null.
value non implementa l'interfaccia IConvertible.
-oppure-
La conversione di value in Char non è supportata.
value è minore di Char.MinValue o maggiore di Char.MaxValue.
Esempio
Nell'esempio seguente viene tentato di convertire ogni elemento in una matrice di oggetti in un Char valore.
object[] values = { 'r', "s", "word", (byte) 83, 77, 109324, 335812911,
new DateTime(2009, 3, 10), (uint) 1934,
(sbyte) -17, 169.34, 175.6m, null };
char result;
foreach (object value in values)
{
try {
result = Convert.ToChar(value);
Console.WriteLine("The {0} value {1} converts to {2}.",
value.GetType().Name, value, result);
}
catch (FormatException e) {
Console.WriteLine(e.Message);
}
catch (InvalidCastException) {
Console.WriteLine("Conversion of the {0} value {1} to a Char is not supported.",
value.GetType().Name, value);
}
catch (OverflowException) {
Console.WriteLine("The {0} value {1} is outside the range of the Char data type.",
value.GetType().Name, value);
}
catch (NullReferenceException) {
Console.WriteLine("Cannot convert a null reference to a Char.");
}
}
// The example displays the following output:
// The Char value r converts to r.
// The String value s converts to s.
// String must be exactly one character long.
// The Byte value 83 converts to S.
// The Int32 value 77 converts to M.
// The Int32 value 109324 is outside the range of the Char data type.
// The Int32 value 335812911 is outside the range of the Char data type.
// Conversion of the DateTime value 3/10/2009 12:00:00 AM to a Char is not supported.
// The UInt32 value 1934 converts to ?.
// The SByte value -17 is outside the range of the Char data type.
// Conversion of the Double value 169.34 to a Char is not supported.
// Conversion of the Decimal value 175.6 to a Char is not supported.
// Cannot convert a null reference to a Char.
let values: obj[] =
[| 'r'; "s"; "word"; 83uy; 77; 109324; 335812911
DateTime(2009, 3, 10); 1934u
-17y; 169.34; 175.6m; null |]
for value in values do
try
let result = Convert.ToChar(value)
printfn $"The {value.GetType().Name} value {value} converts to {result}."
with
| :? FormatException as e ->
printfn $"{e.Message}"
| :? InvalidCastException ->
printfn $"Conversion of the {value.GetType().Name} value {value} to a Char is not supported."
| :? OverflowException ->
printfn $"The {value.GetType().Name} value {value} is outside the range of the Char data type."
| :? NullReferenceException ->
printfn "Cannot convert a null reference to a Char."
// The example displays the following output:
// The Char value r converts to r.
// The String value s converts to s.
// String must be exactly one character long.
// The Byte value 83 converts to S.
// The Int32 value 77 converts to M.
// The Int32 value 109324 is outside the range of the Char data type.
// The Int32 value 335812911 is outside the range of the Char data type.
// Conversion of the DateTime value 3/10/2009 12:00:00 AM to a Char is not supported.
// The UInt32 value 1934 converts to ?.
// The SByte value -17 is outside the range of the Char data type.
// Conversion of the Double value 169.34 to a Char is not supported.
// Conversion of the Decimal value 175.6 to a Char is not supported.
// Cannot convert a null reference to a Char.
Dim values() As Object = { "r"c, "s", "word", CByte(83), 77, 109324, _
335812911, #3/10/2009#, CUInt(1934), _
CSByte(-17), 169.34, 175.6d, Nothing }
Dim result As Char
For Each value As Object In values
Try
result = Convert.ToChar(value)
Console.WriteLine("The {0} value {1} converts to {2}.", _
value.GetType().Name, value, result)
Catch e As FormatException
Console.WriteLine(e.Message)
Catch e As InvalidCastException
Console.WriteLine("Conversion of the {0} value {1} to a Char is not supported.", _
value.GetType().Name, value)
Catch e As OverflowException
Console.WriteLine("The {0} value {1} is outside the range of the Char data type.", _
value.GetType().Name, value)
Catch e As NullReferenceException
Console.WriteLine("Cannot convert a null reference to a Char.")
End Try
Next
' The example displays the following output:
' The Char value r converts to r.
' The String value s converts to s.
' String must be exactly one character long.
' The Byte value 83 converts to S.
' The Int32 value 77 converts to M.
' The Int32 value 109324 is outside the range of the Char data type.
' The Int32 value 335812911 is outside the range of the Char data type.
' Conversion of the DateTime value 3/10/2009 12:00:00 AM to a Char is not supported.
' The UInt32 value 1934 converts to ?.
' The SByte value -17 is outside the range of the Char data type.
' Conversion of the Double value 169.34 to a Char is not supported.
' Conversion of the Decimal value 175.6 to a Char is not supported.
' Cannot convert a null reference to a Char.
Commenti
Se value non nullè , questo metodo esegue il wrapping di una chiamata all'implementazione IConvertible.ToChar del tipo sottostante di value.
Si applica a
ToChar(Object, IFormatProvider)
- Origine:
- Convert.cs
- Origine:
- Convert.cs
- Origine:
- Convert.cs
Converte il valore dell'oggetto specificato nel relativo carattere Unicode equivalente mediante le informazioni di formattazione specifiche delle impostazioni cultura indicate.
public:
static char ToChar(System::Object ^ value, IFormatProvider ^ provider);public static char ToChar (object value, IFormatProvider provider);public static char ToChar (object? value, IFormatProvider? provider);static member ToChar : obj * IFormatProvider -> charPublic Shared Function ToChar (value As Object, provider As IFormatProvider) As CharParametri
- value
- Object
Oggetto che implementa l'interfaccia IConvertible.
- provider
- IFormatProvider
Oggetto che fornisce informazioni di formattazione specifiche delle impostazioni cultura.
Restituisce
Carattere Unicode equivalente a valueo Char.MinValue se value è null.
Eccezioni
value è una stringa Null.
value non implementa l'interfaccia IConvertible.
-oppure-
La conversione di value in Char non è supportata.
value è minore di Char.MinValue o maggiore di Char.MaxValue.
Esempio
Nell'esempio seguente viene definita una classe che implementa e una classe che implementa IConvertibleIFormatProvider. Oggetti della classe che implementa IConvertible una matrice di Double valori. Un oggetto di ogni classe viene passato al ToChar metodo. Questo metodo restituisce un carattere il cui valore Unicode è la media della matrice di Double valori, usando l'oggetto che implementa IFormatProvider per determinare come calcolare la media.
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
Commenti
Il valore restituito è il risultato di richiamare il IConvertible.ToChar metodo del tipo sottostante di value.
provider consente all'utente di specificare informazioni sulla conversione specifiche delle impostazioni cultura sul contenuto di value. I tipi di base ignorano provider; tuttavia, il parametro può essere usato se value è un tipo definito dall'utente che implementa l'interfaccia IConvertible .
Si applica a
ToChar(UInt64)
- Origine:
- Convert.cs
- Origine:
- Convert.cs
- Origine:
- Convert.cs
Importante
Questa API non è conforme a CLS.
Converte il valore dell'intero senza segno a 64 bit specificato nel carattere Unicode equivalente.
public:
static char ToChar(System::UInt64 value);[System.CLSCompliant(false)]
public static char ToChar (ulong value);[<System.CLSCompliant(false)>]
static member ToChar : uint64 -> charPublic Shared Function ToChar (value As ULong) As CharParametri
- value
- UInt64
Intero senza segno a 64 bit da convertire.
Restituisce
Carattere Unicode equivalente a value.
- Attributi
Eccezioni
value è maggiore di Char.MaxValue.
Esempio
Nell'esempio seguente ogni elemento viene convertito in una matrice di interi lunghi senza segno in un Char valore.
ulong[] numbers = { UInt64.MinValue, 40, 160, 255, 1028,
2011, 30001, 207154, Int64.MaxValue };
char result;
foreach (ulong number in numbers)
{
try {
result = Convert.ToChar(number);
Console.WriteLine("{0} converts to '{1}'.", number, result);
}
catch (OverflowException) {
Console.WriteLine("{0} is outside the range of the Char data type.",
number);
}
}
// The example displays the following output:
// 0 converts to ' '.
// 40 converts to '('.
// 160 converts to ' '.
// 255 converts to 'ÿ'.
// 1028 converts to 'Є'.
// 2011 converts to 'ߛ'.
// 30001 converts to '由'.
// 207154 is outside the range of the Char data type.
// 9223372036854775807 is outside the range of the Char data type.
let numbers =
[| UInt64.MinValue; 40uL; 160uL; 255uL; 1028uL
2011uL; 30001uL; 207154uL; uint64 Int64.MaxValue |]
for number in numbers do
try
let result = Convert.ToChar number
printfn $"{number} converts to '{result}'."
with :? OverflowException ->
printfn $"{number} is outside the range of the Char data type."
// The example displays the following output:
// 0 converts to ' '.
// 40 converts to '('.
// 160 converts to ' '.
// 255 converts to 'ÿ'.
// 1028 converts to 'Є'.
// 2011 converts to 'ߛ'.
// 30001 converts to '由'.
// 207154 is outside the range of the Char data type.
// 9223372036854775807 is outside the range of the Char data type.
Dim numbers() As ULong = { UInt64.MinValue, 40, 160, 255, 1028, _
2011, 30001, 207154, Int64.MaxValue }
Dim result As Char
For Each number As ULong In numbers
Try
result = Convert.ToChar(number)
Console.WriteLine("{0} converts to '{1}'.", number, result)
Catch e As OverflowException
Console.WriteLine("{0} is outside the range of the Char data type.", _
number)
End Try
Next
' The example displays the following output:
' 0 converts to ' '.
' 40 converts to '('.
' 160 converts to ' '.
' 255 converts to 'ÿ'.
' 1028 converts to 'Є'.
' 2011 converts to 'ߛ'.
' 30001 converts to '由'.
' 207154 is outside the range of the Char data type.
' 9223372036854775807 is outside the range of the Char data type.
Si applica a
ToChar(UInt32)
- Origine:
- Convert.cs
- Origine:
- Convert.cs
- Origine:
- Convert.cs
Importante
Questa API non è conforme a CLS.
Converte il valore dell'intero senza segno a 32 bit specificato nel carattere Unicode equivalente.
public:
static char ToChar(System::UInt32 value);[System.CLSCompliant(false)]
public static char ToChar (uint value);[<System.CLSCompliant(false)>]
static member ToChar : uint32 -> charPublic Shared Function ToChar (value As UInteger) As CharParametri
- value
- UInt32
Intero senza segno a 32 bit da convertire.
Restituisce
Carattere Unicode equivalente a value.
- Attributi
Eccezioni
value è maggiore di Char.MaxValue.
Esempio
Nell'esempio seguente ogni elemento viene convertito in una matrice di interi senza segno in un Char valore.
uint[] numbers = { UInt32.MinValue, 40, 160, 255, 1028,
2011, 30001, 207154, Int32.MaxValue };
char result;
foreach (uint number in numbers)
{
try {
result = Convert.ToChar(number);
Console.WriteLine("{0} converts to '{1}'.", number, result);
}
catch (OverflowException) {
Console.WriteLine("{0} is outside the range of the Char data type.",
number);
}
}
// The example displays the following output:
// 0 converts to ' '.
// 40 converts to '('.
// 160 converts to ' '.
// 255 converts to 'ÿ'.
// 1028 converts to 'Є'.
// 2011 converts to 'ߛ'.
// 30001 converts to '由'.
// 207154 is outside the range of the Char data type.
// 2147483647 is outside the range of the Char data type.
let numbers =
[| UInt32.MinValue; 40u; 160u; 255u; 1028u
2011u; 30001u; 207154u; uint Int32.MaxValue |]
for number in numbers do
try
let result = Convert.ToChar number
printfn $"{number} converts to '{result}'."
with :? OverflowException ->
printfn $"{number} is outside the range of the Char data type."
// The example displays the following output:
// 0 converts to ' '.
// 40 converts to '('.
// 160 converts to ' '.
// 255 converts to 'ÿ'.
// 1028 converts to 'Є'.
// 2011 converts to 'ߛ'.
// 30001 converts to '由'.
// 207154 is outside the range of the Char data type.
// 2147483647 is outside the range of the Char data type.
Dim numbers() As UInteger = { UInt32.MinValue, 40, 160, 255, 1028, _
2011, 30001, 207154, Int32.MaxValue }
Dim result As Char
For Each number As UInteger In numbers
Try
result = Convert.ToChar(number)
Console.WriteLine("{0} converts to '{1}'.", number, result)
Catch e As OverflowException
Console.WriteLine("{0} is outside the range of the Char data type.", _
number)
End Try
Next
' The example displays the following output:
' 0 converts to ' '.
' 40 converts to '('.
' 160 converts to ' '.
' 255 converts to 'ÿ'.
' 1028 converts to 'Є'.
' 2011 converts to 'ߛ'.
' 30001 converts to '由'.
' 207154 is outside the range of the Char data type.
' 2147483647 is outside the range of the Char data type.
Si applica a
ToChar(UInt16)
- Origine:
- Convert.cs
- Origine:
- Convert.cs
- Origine:
- Convert.cs
Importante
Questa API non è conforme a CLS.
Converte il valore dell'intero senza segno a 16 bit specificato nel carattere Unicode equivalente.
public:
static char ToChar(System::UInt16 value);[System.CLSCompliant(false)]
public static char ToChar (ushort value);[<System.CLSCompliant(false)>]
static member ToChar : uint16 -> charPublic Shared Function ToChar (value As UShort) As CharParametri
- value
- UInt16
Intero senza segno a 16 bit da convertire.
Restituisce
Carattere Unicode equivalente a value.
- Attributi
Esempio
Nell'esempio seguente ogni elemento viene convertito in una matrice di interi senza segno a 16 bit in un Char valore.
ushort[] numbers = { UInt16.MinValue, 40, 160, 255, 1028,
2011, UInt16.MaxValue };
char result;
foreach (ushort number in numbers)
{
result = Convert.ToChar(number);
Console.WriteLine("{0} converts to '{1}'.", number, result);
}
// The example displays the following output:
// 0 converts to ' '.
// 40 converts to '('.
// 160 converts to ' '.
// 255 converts to 'ÿ'.
// 1028 converts to 'Є'.
// 2011 converts to 'ߛ'.
// 65535 converts to ''.
let numbers =
[| UInt16.MinValue; 40us; 160us; 255us
1028us; 2011us; UInt16.MaxValue |]
for number in numbers do
let result = Convert.ToChar number
printfn $"{number} converts to '{result}'."
// The example displays the following output:
// 0 converts to ' '.
// 40 converts to '('.
// 160 converts to ' '.
// 255 converts to 'ÿ'.
// 1028 converts to 'Є'.
// 2011 converts to 'ߛ'.
// 65535 converts to ''.
Dim numbers() As UShort = { UInt16.MinValue, 40, 160, 255, 1028, _
2011, UInt16.MaxValue }
Dim result As Char
For Each number As UShort In numbers
result = Convert.ToChar(number)
Console.WriteLine("{0} converts to '{1}'.", number, result)
Next
' The example displays the following output:
' 0 converts to ' '.
' 40 converts to '('.
' 160 converts to ' '.
' 255 converts to 'ÿ'.
' 1028 converts to 'Є'.
' 2011 converts to 'ߛ'.
' 65535 converts to ''.
Si applica a
ToChar(String)
- Origine:
- Convert.cs
- Origine:
- Convert.cs
- Origine:
- Convert.cs
Converte il primo carattere di una stringa specificata in un carattere Unicode.
public:
static char ToChar(System::String ^ value);public static char ToChar (string value);static member ToChar : string -> charPublic Shared Function ToChar (value As String) As CharParametri
- value
- String
Stringa di lunghezza 1.
Restituisce
Carattere Unicode equivalente al primo e unico carattere in value.
Eccezioni
value è null.
La lunghezza di value non è 1.
Esempio
Nell'esempio seguente ogni elemento viene convertito in una matrice di stringhe in un Char valore.
string nullString = null;
string[] strings = { "A", "This", '\u0007'.ToString(), nullString };
char result;
foreach (string strng in strings)
{
try {
result = Convert.ToChar(strng);
Console.WriteLine("'{0}' converts to '{1}'.", strng, result);
}
catch (FormatException)
{
Console.WriteLine("'{0}' is not in the correct format for conversion to a Char.",
strng);
}
catch (ArgumentNullException) {
Console.WriteLine("A null string cannot be converted to a Char.");
}
}
// The example displays the following output:
// 'A' converts to 'A'.
// 'This' is not in the correct format for conversion to a Char.
// ' ' converts to ' '.
// A null string cannot be converted to a Char.
let nullString = null
let strings = [| "A"; "This"; '\u0007'.ToString(); nullString |]
for string in strings do
try
let result = Convert.ToChar string
printfn $"'{string}' converts to '{result}'."
with
| :? FormatException ->
printfn $"'{string}' is not in the correct format for conversion to a Char."
| :? ArgumentNullException ->
printfn "A null string cannot be converted to a Char."
// The example displays the following output:
// 'A' converts to 'A'.
// 'This' is not in the correct format for conversion to a Char.
// ' ' converts to ' '.
// A null string cannot be converted to a Char.
Dim nullString As String = Nothing
Dim strings() As String = { "A", "This", vbTab, nullString }
Dim result As Char
For Each strng As String In strings
Try
result = Convert.ToChar(strng)
Console.WriteLine("'{0}' converts to '{1}'.", strng, result)
Catch e As FormatException
Console.WriteLine("'{0}' is not in the correct format for conversion to a Char.", _
strng)
Catch e As ArgumentNullException
Console.WriteLine("A null string cannot be converted to a Char.")
End Try
Next
' The example displays the following output:
' 'A' converts to 'A'.
' 'This' is not in the correct format for conversion to a Char.
' ' ' converts to ' '.
' A null string cannot be converted to a Char.
Commenti
value deve essere una stringa contenente un singolo carattere.
Se si preferisce non gestire un'eccezione se la conversione ha esito negativo, è possibile chiamare invece il Char.TryParse metodo. Restituisce un Boolean valore che indica se la conversione ha avuto esito positivo o negativo.
Si applica a
ToChar(Single)
- Origine:
- Convert.cs
- Origine:
- Convert.cs
- Origine:
- Convert.cs
La chiamata di questo metodo genera sempre un'eccezione InvalidCastException.
public:
static char ToChar(float value);public static char ToChar (float value);static member ToChar : single -> charPublic Shared Function ToChar (value As Single) As CharParametri
- value
- Single
Numero a virgola mobile a precisione singola da convertire.
Restituisce
Questa conversione non è supportata. Non vengono restituiti valori.
Eccezioni
Questa conversione non è supportata.
Si applica a
ToChar(SByte)
- Origine:
- Convert.cs
- Origine:
- Convert.cs
- Origine:
- Convert.cs
Importante
Questa API non è conforme a CLS.
Converte il valore dell'intero con segno a 8 bit specificato nel carattere Unicode equivalente.
public:
static char ToChar(System::SByte value);[System.CLSCompliant(false)]
public static char ToChar (sbyte value);[<System.CLSCompliant(false)>]
static member ToChar : sbyte -> charPublic Shared Function ToChar (value As SByte) As CharParametri
- value
- SByte
Intero con segno a 8 bit da convertire.
Restituisce
Carattere Unicode equivalente a value.
- Attributi
Eccezioni
value è minore di Char.MinValue.
Esempio
L'esempio seguente converte una matrice di byte firmati in Char valori.
sbyte[] numbers = { SByte.MinValue, -1, 40, 80, 120, SByte.MaxValue };
char result;
foreach (sbyte number in numbers)
{
try {
result = Convert.ToChar(number);
Console.WriteLine("{0} converts to '{1}'.", number, result);
}
catch (OverflowException) {
Console.WriteLine("{0} is outside the range of the Char data type.",
number);
}
}
// The example displays the following output:
// -128 is outside the range of the Char data type.
// -1 is outside the range of the Char data type.
// 40 converts to '('.
// 80 converts to 'P'.
// 120 converts to 'x'.
// 127 converts to '⌂'.
let numbers =
[| SByte.MinValue; -1y; 40y; 80y; 120y; SByte.MaxValue |]
for number in numbers do
try
let result = Convert.ToChar number
printfn $"{number} converts to '{result}'."
with :? OverflowException ->
printfn $"{number} is outside the range of the Char data type."
// The example displays the following output:
// -128 is outside the range of the Char data type.
// -1 is outside the range of the Char data type.
// 40 converts to '('.
// 80 converts to 'P'.
// 120 converts to 'x'.
// 127 converts to '⌂'.
Dim numbers() As SByte = { SByte.MinValue, -1, 40, 80, 120, SByte.MaxValue }
Dim result As Char
For Each number As SByte In numbers
Try
result = Convert.ToChar(number)
Console.WriteLine("{0} converts to '{1}'.", number, result)
Catch e As OverflowException
Console.WriteLine("{0} is outside the range of the Char data type.", _
number)
End Try
Next
' The example displays the following output:
' -128 is outside the range of the Char data type.
' -1 is outside the range of the Char data type.
' 40 converts to '('.
' 80 converts to 'P'.
' 120 converts to 'x'.
' 127 converts to '⌂'.
Si applica a
ToChar(Int64)
- Origine:
- Convert.cs
- Origine:
- Convert.cs
- Origine:
- Convert.cs
Converte il valore dell'intero con segno a 64 bit specificato nel carattere Unicode equivalente.
public:
static char ToChar(long value);public static char ToChar (long value);static member ToChar : int64 -> charPublic Shared Function ToChar (value As Long) As CharParametri
- value
- Int64
Intero con segno a 64 bit da convertire.
Restituisce
Carattere Unicode equivalente a value.
Eccezioni
value è minore di Char.MinValue o maggiore di Char.MaxValue.
Esempio
L'esempio seguente tenta di convertire un intero lungo in un Charoggetto e genera un OverflowException errore.
public:
void ConvertLongChar( Int64 longVal )
{
Char charVal = 'a';
try
{
charVal = System::Convert::ToChar( longVal );
System::Console::WriteLine( " {0} as a char is {1}",
longVal, charVal );
}
catch ( System::OverflowException^ )
{
System::Console::WriteLine( "Overflow in long-to-char conversion." );
}
// A conversion from Char to long cannot overflow.
longVal = System::Convert::ToInt64( charVal );
System::Console::WriteLine( " {0} as an Int64 is {1}",
charVal, longVal );
}
public void ConvertLongChar(long longVal) {
char charVal = 'a';
try {
charVal = System.Convert.ToChar(longVal);
System.Console.WriteLine("{0} as a char is {1}",
longVal, charVal);
}
catch (System.OverflowException) {
System.Console.WriteLine(
"Overflow in long-to-char conversion.");
}
// A conversion from Char to long cannot overflow.
longVal = System.Convert.ToInt64(charVal);
System.Console.WriteLine("{0} as an Int64 is {1}",
charVal, longVal);
}
let convertLongChar (longVal: int64) =
let charVal = 'a'
try
let charVal = Convert.ToChar longVal
printfn $"{longVal} as a char is {charVal}"
with :? OverflowException ->
printfn "Overflow in long-to-char conversion."
// A conversion from Char to long cannot overflow.
let longVal = Convert.ToInt64 charVal
printfn $"{charVal} as an Int64 is {longVal}"
Public Sub ConvertLongChar(ByVal longVal As Long)
Dim charVal As Char = "a"c
Try
charVal = System.Convert.ToChar(longVal)
System.Console.WriteLine("{0} as a char is {1}", _
longVal, charVal)
Catch exception As System.OverflowException
System.Console.WriteLine( _
"Overflow in Long-to-Char conversion.")
End Try
' A conversion from Char to Long cannot overflow.
longVal = System.Convert.ToInt64(charVal)
System.Console.WriteLine("{0} as a Long is {1}", _
charVal, longVal)
End Sub
Si applica a
ToChar(Int16)
- Origine:
- Convert.cs
- Origine:
- Convert.cs
- Origine:
- Convert.cs
Converte il valore dell'intero con segno a 16 bit specificato nel carattere Unicode equivalente.
public:
static char ToChar(short value);public static char ToChar (short value);static member ToChar : int16 -> charPublic Shared Function ToChar (value As Short) As CharParametri
- value
- Int16
Intero con segno a 16 bit da convertire.
Restituisce
Carattere Unicode equivalente a value.
Eccezioni
value è minore di Char.MinValue.
Esempio
L'esempio seguente converte una matrice di numeri interi a 16 bit firmati in Char valori.
short[] numbers = { Int16.MinValue, 0, 40, 160, 255, 1028,
2011, Int16.MaxValue };
char result;
foreach (short number in numbers)
{
try {
result = Convert.ToChar(number);
Console.WriteLine("{0} converts to '{1}'.", number, result);
}
catch (OverflowException) {
Console.WriteLine("{0} is outside the range of the Char data type.",
number);
}
}
// The example displays the following output:
// -32768 is outside the range of the Char data type.
// 0 converts to ' '.
// 40 converts to '('.
// 160 converts to ' '.
// 255 converts to 'ÿ'.
// 1028 converts to 'Є'.
// 2011 converts to 'ߛ'.
// 32767 converts to '翿'.
let numbers =
[| Int16.MinValue; 0s; 40s; 160s
255s; 1028s; 2011s; Int16.MaxValue |]
for number in numbers do
try
let result = Convert.ToChar number
printfn $"{number} converts to '{result}'."
with :? OverflowException ->
printfn $"{number} is outside the range of the Char data type."
// The example displays the following output:
// -32768 is outside the range of the Char data type.
// 0 converts to ' '.
// 40 converts to '('.
// 160 converts to ' '.
// 255 converts to 'ÿ'.
// 1028 converts to 'Є'.
// 2011 converts to 'ߛ'.
// 32767 converts to '翿'.
Dim numbers() As Short = { Int16.MinValue, 0, 40, 160, 255, 1028, _
2011, Int16.MaxValue }
Dim result As Char
For Each number As Short In numbers
Try
result = Convert.ToChar(number)
Console.WriteLine("{0} converts to '{1}'.", number, result)
Catch e As OverflowException
Console.WriteLine("{0} is outside the range of the Char data type.", _
number)
End Try
Next
' The example displays the following output:
' -32768 is outside the range of the Char data type.
' 0 converts to ' '.
' 40 converts to '('.
' 160 converts to ' '.
' 255 converts to 'ÿ'.
' 1028 converts to 'Є'.
' 2011 converts to 'ߛ'.
' 32767 converts to '翿'.
Si applica a
ToChar(Double)
- Origine:
- Convert.cs
- Origine:
- Convert.cs
- Origine:
- Convert.cs
La chiamata di questo metodo genera sempre un'eccezione InvalidCastException.
public:
static char ToChar(double value);public static char ToChar (double value);static member ToChar : double -> charPublic Shared Function ToChar (value As Double) As CharParametri
- value
- Double
Numero a virgola mobile a precisione doppia da convertire.
Restituisce
Questa conversione non è supportata. Non vengono restituiti valori.
Eccezioni
Questa conversione non è supportata.
Si applica a
ToChar(Decimal)
- Origine:
- Convert.cs
- Origine:
- Convert.cs
- Origine:
- Convert.cs
La chiamata di questo metodo genera sempre un'eccezione InvalidCastException.
public:
static char ToChar(System::Decimal value);public static char ToChar (decimal value);static member ToChar : decimal -> charPublic Shared Function ToChar (value As Decimal) As CharParametri
- value
- Decimal
Numero decimale da convertire.
Restituisce
Questa conversione non è supportata. Non vengono restituiti valori.
Eccezioni
Questa conversione non è supportata.
Esempio
L'esempio seguente tenta di convertire un Decimal oggetto in Chare genera un InvalidCastException errore.
public:
void ConvertCharDecimal( Char charVal )
{
Decimal decimalVal = 0;
// Char to decimal conversion is not supported and will always
// throw an InvalidCastException.
try
{
decimalVal = System::Convert::ToDecimal( charVal );
}
catch ( System::InvalidCastException^ )
{
System::Console::WriteLine(
"Char-to-Decimal conversion is not supported by the .NET Framework." );
}
//Decimal to char conversion is also not supported.
try
{
charVal = System::Convert::ToChar( decimalVal );
}
catch ( System::InvalidCastException^ )
{
System::Console::WriteLine(
"Decimal-to-Char conversion is not supported by the .NET Framework." );
}
}
public void ConvertCharDecimal(char charVal) {
Decimal decimalVal = 0;
// Char to decimal conversion is not supported and will always
// throw an InvalidCastException.
try {
decimalVal = System.Convert.ToDecimal(charVal);
}
catch (System.InvalidCastException) {
System.Console.WriteLine(
"Char-to-Decimal conversion is not supported " +
"by the .NET Framework.");
}
//Decimal to char conversion is also not supported.
try {
charVal = System.Convert.ToChar(decimalVal);
}
catch (System.InvalidCastException) {
System.Console.WriteLine(
"Decimal-to-Char conversion is not supported " +
"by the .NET Framework.");
}
}
let convertCharDecimal (charVal: char) =
let decimalVal = 0m
// Char to decimal conversion is not supported and will always
// throw an InvalidCastException.
try
let decimalVal = Convert.ToDecimal charVal
()
with :? InvalidCastException ->
printfn "Char-to-Decimal conversion is not supported by the .NET Runtime."
//Decimal to char conversion is also not supported.
try
let charVal = Convert.ToChar decimalVal
()
with :? InvalidCastException ->
printfn "Decimal-to-Char conversion is not supported by the .NET Runtime."
Public Sub ConvertCharDecimal(ByVal charVal As Char)
Dim decimalVal As [Decimal] = 0
' Char to decimal conversion is not supported and will always
' throw an InvalidCastException.
Try
decimalVal = System.Convert.ToDecimal(charVal)
Catch exception As System.InvalidCastException
System.Console.WriteLine( _
"Char-to-Decimal conversion is not supported " + _
"by the .NET Framework.")
End Try
'Decimal to char conversion is also not supported.
Try
charVal = System.Convert.ToChar(decimalVal)
Catch exception As System.InvalidCastException
System.Console.WriteLine( _
"Decimal-to-Char conversion is not supported " + _
"by the .NET Framework.")
End Try
End Sub
Si applica a
ToChar(DateTime)
- Origine:
- Convert.cs
- Origine:
- Convert.cs
- Origine:
- Convert.cs
La chiamata di questo metodo genera sempre un'eccezione InvalidCastException.
public:
static char ToChar(DateTime value);public static char ToChar (DateTime value);static member ToChar : DateTime -> charPublic Shared Function ToChar (value As DateTime) As CharParametri
- value
- DateTime
Valore di data e ora da convertire.
Restituisce
Questa conversione non è supportata. Non vengono restituiti valori.
Eccezioni
Questa conversione non è supportata.
Si applica a
ToChar(Char)
- Origine:
- Convert.cs
- Origine:
- Convert.cs
- Origine:
- Convert.cs
Restituisce il valore del carattere Unicode specificato; non viene eseguita alcuna conversione effettiva.
public:
static char ToChar(char value);public static char ToChar (char value);static member ToChar : char -> charPublic Shared Function ToChar (value As Char) As CharParametri
- value
- Char
Carattere Unicode da restituire.
Restituisce
value viene restituito invariato.
Si applica a
ToChar(Byte)
- Origine:
- Convert.cs
- Origine:
- Convert.cs
- Origine:
- Convert.cs
Converte il valore dell'intero senza segno a 8 bit specificato nel carattere Unicode equivalente.
public:
static char ToChar(System::Byte value);public static char ToChar (byte value);static member ToChar : byte -> charPublic Shared Function ToChar (value As Byte) As CharParametri
- value
- Byte
Intero senza segno a 8 bit da convertire.
Restituisce
Carattere Unicode equivalente a value.
Esempio
L'esempio seguente converte una matrice di byte senza segno in Char valori.
byte[] bytes = {Byte.MinValue, 40, 80, 120, 180, Byte.MaxValue};
char result;
foreach (byte number in bytes)
{
result = Convert.ToChar(number);
Console.WriteLine("{0} converts to '{1}'.", number, result);
}
// The example displays the following output:
// 0 converts to ' '.
// 40 converts to '('.
// 80 converts to 'P'.
// 120 converts to 'x'.
// 180 converts to '''.
// 255 converts to 'ÿ'.
let bytes =
[| Byte.MinValue; 40uy; 80uy; 120uy; 180uy; Byte.MaxValue|]
for number in bytes do
let result = Convert.ToChar number
printfn $"{number} converts to '{result}'."
// The example displays the following output:
// 0 converts to ' '.
// 40 converts to '('.
// 80 converts to 'P'.
// 120 converts to 'x'.
// 180 converts to '''.
// 255 converts to 'ÿ'.
Dim bytes() As Byte = {Byte.MinValue, 40, 80, 120, 180, Byte.MaxValue}
Dim result As Char
For Each number As Byte In bytes
result = Convert.ToChar(number)
Console.WriteLine("{0} converts to '{1}'.", number, result)
Next
' The example displays the following output:
' 0 converts to ' '.
' 40 converts to '('.
' 80 converts to 'P'.
' 120 converts to 'x'.
' 180 converts to '''.
' 255 converts to 'ÿ'.
Si applica a
ToChar(Boolean)
- Origine:
- Convert.cs
- Origine:
- Convert.cs
- Origine:
- Convert.cs
La chiamata di questo metodo genera sempre un'eccezione InvalidCastException.
public:
static char ToChar(bool value);public static char ToChar (bool value);static member ToChar : bool -> charPublic Shared Function ToChar (value As Boolean) As CharParametri
- value
- Boolean
Valore booleano da convertire.
Restituisce
Questa conversione non è supportata. Non vengono restituiti valori.
Eccezioni
Questa conversione non è supportata.
Si applica a
ToChar(Int32)
- Origine:
- Convert.cs
- Origine:
- Convert.cs
- Origine:
- Convert.cs
Converte il valore dell'intero con segno a 32 bit specificato nel carattere Unicode equivalente.
public:
static char ToChar(int value);public static char ToChar (int value);static member ToChar : int -> charPublic Shared Function ToChar (value As Integer) As CharParametri
- value
- Int32
Intero con segno a 32 bit da convertire.
Restituisce
Carattere Unicode equivalente a value.
Eccezioni
value è minore di Char.MinValue o maggiore di Char.MaxValue.
Esempio
L'esempio seguente converte una matrice di interi firmati in Char valori.
int[] numbers = { -1, 0, 40, 160, 255, 1028,
2011, 30001, 207154, Int32.MaxValue };
char result;
foreach (int number in numbers)
{
try {
result = Convert.ToChar(number);
Console.WriteLine("{0} converts to '{1}'.", number, result);
}
catch (OverflowException) {
Console.WriteLine("{0} is outside the range of the Char data type.",
number);
}
}
// -1 is outside the range of the Char data type.
// 0 converts to ' '.
// 40 converts to '('.
// 160 converts to ' '.
// 255 converts to 'ÿ'.
// 1028 converts to 'Є'.
// 2011 converts to 'ߛ'.
// 30001 converts to '由'.
// 207154 is outside the range of the Char data type.
// 2147483647 is outside the range of the Char data type.
let numbers =
[| -1; 0; 40; 160; 255; 1028; 2011
30001; 207154; Int32.MaxValue |]
for number in numbers do
try
let result = Convert.ToChar number
printfn $"{number} converts to '{result}'."
with :? OverflowException ->
printfn $"{number} is outside the range of the Char data type."
// -1 is outside the range of the Char data type.
// 0 converts to ' '.
// 40 converts to '('.
// 160 converts to ' '.
// 255 converts to 'ÿ'.
// 1028 converts to 'Є'.
// 2011 converts to 'ߛ'.
// 30001 converts to '由'.
// 207154 is outside the range of the Char data type.
// 2147483647 is outside the range of the Char data type.
Dim numbers() As Integer = { -1, 0, 40, 160, 255, 1028, _
2011, 30001, 207154, Int32.MaxValue }
Dim result As Char
For Each number As Integer In numbers
Try
result = Convert.ToChar(number)
Console.WriteLine("{0} converts to '{1}'.", number, result)
Catch e As OverflowException
Console.WriteLine("{0} is outside the range of the Char data type.", _
number)
End Try
Next
' -1 is outside the range of the Char data type.
' 0 converts to ' '.
' 40 converts to '('.
' 160 converts to ' '.
' 255 converts to 'ÿ'.
' 1028 converts to 'Є'.
' 2011 converts to 'ߛ'.
' 30001 converts to '由'.
' 207154 is outside the range of the Char data type.
' 2147483647 is outside the range of the Char data type.
Si applica a
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