Byte.TryParse Method
Important
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Tries to convert the string representation of a number to its Byte equivalent, and returns a value that indicates whether the conversion succeeded.
TryParse(ReadOnlySpan<Byte>, IFormatProvider, Byte) |
Tries to parse a span of UTF-8 characters into a value. |
TryParse(ReadOnlySpan<Char>, Byte) |
Tries to convert the span representation of a number to its Byte equivalent, and returns a value that indicates whether the conversion succeeded. |
TryParse(String, Byte) |
Tries to convert the string representation of a number to its Byte equivalent, and returns a value that indicates whether the conversion succeeded. |
TryParse(ReadOnlySpan<Char>, IFormatProvider, Byte) |
Tries to parse a span of characters into a value. |
TryParse(String, IFormatProvider, Byte) |
Tries to parse a string into a value. |
TryParse(ReadOnlySpan<Byte>, NumberStyles, IFormatProvider, Byte) |
Tries to parse a span of UTF-8 characters into a value. |
TryParse(ReadOnlySpan<Byte>, Byte) |
Tries to convert a UTF-8 character span containing the string representation of a number to its 8-bit unsigned integer equivalent. |
TryParse(ReadOnlySpan<Char>, NumberStyles, IFormatProvider, Byte) |
Converts the span representation of a number in a specified style and culture-specific format to its Byte equivalent. A return value indicates whether the conversion succeeded or failed. |
TryParse(String, NumberStyles, IFormatProvider, Byte) |
Converts the string representation of a number in a specified style and culture-specific format to its Byte equivalent. A return value indicates whether the conversion succeeded or failed. |
- Source:
- Byte.cs
- Source:
- Byte.cs
Tries to parse a span of UTF-8 characters into a value.
public:
static bool TryParse(ReadOnlySpan<System::Byte> utf8Text, IFormatProvider ^ provider, [Runtime::InteropServices::Out] System::Byte % result) = IUtf8SpanParsable<System::Byte>::TryParse;
public static bool TryParse (ReadOnlySpan<byte> utf8Text, IFormatProvider? provider, out byte result);
static member TryParse : ReadOnlySpan<byte> * IFormatProvider * byte -> bool
Public Shared Function TryParse (utf8Text As ReadOnlySpan(Of Byte), provider As IFormatProvider, ByRef result As Byte) As Boolean
Parameters
- utf8Text
- ReadOnlySpan<Byte>
The span of UTF-8 characters to parse.
- provider
- IFormatProvider
An object that provides culture-specific formatting information about utf8Text
.
- result
- Byte
On return, contains the result of successfully parsing utf8Text
or an undefined value on failure.
Returns
true
if utf8Text
was successfully parsed; otherwise, false
.
Applies to
.NET 9 dan .NET 8
Produk | Versi |
---|---|
.NET | 8, 9 |
- Source:
- Byte.cs
- Source:
- Byte.cs
- Source:
- Byte.cs
Tries to convert the span representation of a number to its Byte equivalent, and returns a value that indicates whether the conversion succeeded.
public:
static bool TryParse(ReadOnlySpan<char> s, [Runtime::InteropServices::Out] System::Byte % result);
public static bool TryParse (ReadOnlySpan<char> s, out byte result);
static member TryParse : ReadOnlySpan<char> * byte -> bool
Public Shared Function TryParse (s As ReadOnlySpan(Of Char), ByRef result As Byte) As Boolean
Parameters
- s
- ReadOnlySpan<Char>
A span containing the characters representing the number to convert.
- result
- Byte
When this method returns, contains the Byte value equivalent to the number contained in s
if the conversion succeeded, or zero if the conversion failed. This parameter is passed uninitialized; any value originally supplied in result
will be overwritten.
Returns
true
if s
was converted successfully; otherwise, false
.
Applies to
.NET 9 dan versi lain
Produk | Versi |
---|---|
.NET | Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Standard | 2.1 |
- Source:
- Byte.cs
- Source:
- Byte.cs
- Source:
- Byte.cs
Tries to convert the string representation of a number to its Byte equivalent, and returns a value that indicates whether the conversion succeeded.
public:
static bool TryParse(System::String ^ s, [Runtime::InteropServices::Out] System::Byte % result);
public static bool TryParse (string s, out byte result);
public static bool TryParse (string? s, out byte result);
static member TryParse : string * byte -> bool
Public Shared Function TryParse (s As String, ByRef result As Byte) As Boolean
Parameters
- s
- String
A string that contains a number to convert.
- result
- Byte
When this method returns, contains the Byte value equivalent to the number contained in s
if the conversion succeeded, or zero if the conversion failed. This parameter is passed uninitialized; any value originally supplied in result
will be overwritten.
Returns
true
if s
was converted successfully; otherwise, false
.
Examples
The following example calls the TryParse(String, Byte) method with a number of different string values.
using namespace System;
void main()
{
array<String^>^ byteStrings = gcnew array<String^> { nullptr, String::Empty,
"1024", "100.1", "100",
"+100", "-100", "000000000000000100",
"00,100", " 20 ", "FF", "0x1F" };
Byte byteValue;
for each (String^ byteString in byteStrings) {
bool result = Byte::TryParse(byteString, byteValue);
if (result)
Console::WriteLine("Converted '{0}' to {1}",
byteString, byteValue);
else
Console::WriteLine("Attempted conversion of '{0}' failed.",
byteString);
}
}
// The example displays the following output:
// Attempted conversion of '' failed.
// Attempted conversion of '' failed.`
// Attempted conversion of '1024' failed.
// Attempted conversion of '100.1' failed.
// Converted '100' to 100
// Converted '+100' to 100
// Attempted conversion of '-100' failed.
// Converted '000000000000000100' to 100
// Attempted conversion of '00,100' failed.
// Converted ' 20 ' to 20
// Attempted conversion of 'FF' failed.
// Attempted conversion of '0x1F' failed.}
using System;
public class ByteConversion
{
public static void Main()
{
string[] byteStrings = { null, string.Empty, "1024",
"100.1", "100", "+100", "-100",
"000000000000000100", "00,100",
" 20 ", "FF", "0x1F" };
foreach (var byteString in byteStrings)
{
CallTryParse(byteString);
}
}
private static void CallTryParse(string stringToConvert)
{
byte byteValue;
bool success = Byte.TryParse(stringToConvert, out byteValue);
if (success)
{
Console.WriteLine("Converted '{0}' to {1}",
stringToConvert, byteValue);
}
else
{
Console.WriteLine("Attempted conversion of '{0}' failed.",
stringToConvert);
}
}
}
// The example displays the following output to the console:
// Attempted conversion of '' failed.
// Attempted conversion of '' failed.
// Attempted conversion of '1024' failed.
// Attempted conversion of '100.1' failed.
// Converted '100' to 100
// Converted '+100' to 100
// Attempted conversion of '-100' failed.
// Converted '000000000000000100' to 100
// Attempted conversion of '00,100' failed.
// Converted ' 20 ' to 20
// Attempted conversion of 'FF' failed.
// Attempted conversion of '0x1F' failed.
open System
let callTryParse (stringToConvert: string) =
match Byte.TryParse stringToConvert with
| true, byteValue ->
printfn $"Converted '{stringToConvert}' to {byteValue}"
| _ ->
printfn $"Attempted conversion of '{stringToConvert}' failed."
let byteStrings =
[ null; String.Empty; "1024"
"100.1"; "100"; "+100"; "-100"
"000000000000000100"; "00,100"
" 20 "; "FF"; "0x1F" ]
for byteString in byteStrings do
callTryParse byteString
// The example displays the following output to the console:
// Attempted conversion of '' failed.
// Attempted conversion of '' failed.
// Attempted conversion of '1024' failed.
// Attempted conversion of '100.1' failed.
// Converted '100' to 100
// Converted '+100' to 100
// Attempted conversion of '-100' failed.
// Converted '000000000000000100' to 100
// Attempted conversion of '00,100' failed.
// Converted ' 20 ' to 20
// Attempted conversion of 'FF' failed.
// Attempted conversion of '0x1F' failed.
Module ByteConversion
Public Sub Main()
Dim byteStrings() As String = { Nothing, String.Empty, "1024",
"100.1", "100", "+100", "-100",
"000000000000000100", "00,100",
" 20 ", "FF", "0x1F"}
For Each byteString As String In byteStrings
CallTryParse(byteString)
Next
End Sub
Private Sub CallTryParse(stringToConvert As String)
Dim byteValue As Byte
Dim success As Boolean = Byte.TryParse(stringToConvert, byteValue)
If success Then
Console.WriteLine("Converted '{0}' to {1}", _
stringToConvert, byteValue)
Else
Console.WriteLine("Attempted conversion of '{0}' failed.", _
stringToConvert)
End If
End Sub
End Module
' The example displays the following output to the console:
' Attempted conversion of '' failed.
' Attempted conversion of '' failed.
' Attempted conversion of '1024' failed.
' Attempted conversion of '100.1' failed.
' Converted '100' to 100
' Converted '+100' to 100
' Attempted conversion of '-100' failed.
' Converted '000000000000000100' to 100
' Attempted conversion of '00,100' failed.
' Converted ' 20 ' to 20
' Attempted conversion of 'FF' failed.
' Attempted conversion of '0x1F' failed.
Remarks
The conversion fails and the method returns false
if the s
parameter is not in the correct format, if it is null
or String.Empty, or if it represents a number less than MinValue or greater than MaxValue.
The Byte.TryParse(String, Byte) method is similar to the Byte.Parse(String) method, except that TryParse(String, Byte) does not throw an exception if the conversion fails.
The s
parameter should be the string representation of a number in the following form:
[ws][sign]digits[ws]
Elements in square brackets ([ and ]) are optional. The following table describes each element.
Element | Description |
---|---|
ws | Optional white space. |
sign | An optional positive sign, as specified by the NumberFormatInfo.PositiveSign property of the current culture. |
digits | A sequence of decimal digits that range from 0 to 9. |
The s
parameter is interpreted using the Integer style. In addition to the byte value's decimal digits, only leading and trailing spaces together with a leading sign are allowed. (If the sign is present, it must be a positive sign or the method throws an OverflowException.) To explicitly define the style elements together with the culture-specific formatting information that can be present in s
, use the Byte.Parse(String, NumberStyles, IFormatProvider) method.
The s
parameter is parsed using the formatting information in a NumberFormatInfo object for the current culture. For more information, see NumberFormatInfo.CurrentInfo.
This overload of the Byte.TryParse(String, Byte) method interprets all digits in the s
parameter as decimal digits. To parse the string representation of a hexadecimal number, call the Byte.TryParse(String, NumberStyles, IFormatProvider, Byte) overload.
See also
- Sample: .NET Core WinForms Formatting Utility (C#)
- Sample: .NET Core WinForms Formatting Utility (Visual Basic)
Applies to
.NET 9 dan versi lain
Produk | Versi |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 2.0, 2.1 |
UWP | 10.0 |
- Source:
- Byte.cs
- Source:
- Byte.cs
- Source:
- Byte.cs
Tries to parse a span of characters into a value.
public:
static bool TryParse(ReadOnlySpan<char> s, IFormatProvider ^ provider, [Runtime::InteropServices::Out] System::Byte % result) = ISpanParsable<System::Byte>::TryParse;
public static bool TryParse (ReadOnlySpan<char> s, IFormatProvider? provider, out byte result);
static member TryParse : ReadOnlySpan<char> * IFormatProvider * byte -> bool
Public Shared Function TryParse (s As ReadOnlySpan(Of Char), provider As IFormatProvider, ByRef result As Byte) As Boolean
Parameters
- s
- ReadOnlySpan<Char>
The span of characters to parse.
- provider
- IFormatProvider
An object that provides culture-specific formatting information about s
.
- result
- Byte
When this method returns, contains the result of successfully parsing s
, or an undefined value on failure.
Returns
true
if s
was successfully parsed; otherwise, false
.
Applies to
.NET 9 dan versi lain
Produk | Versi |
---|---|
.NET | 7, 8, 9 |
- Source:
- Byte.cs
- Source:
- Byte.cs
- Source:
- Byte.cs
Tries to parse a string into a value.
public:
static bool TryParse(System::String ^ s, IFormatProvider ^ provider, [Runtime::InteropServices::Out] System::Byte % result) = IParsable<System::Byte>::TryParse;
public static bool TryParse (string? s, IFormatProvider? provider, out byte result);
static member TryParse : string * IFormatProvider * byte -> bool
Public Shared Function TryParse (s As String, provider As IFormatProvider, ByRef result As Byte) As Boolean
Parameters
- s
- String
The string to parse.
- provider
- IFormatProvider
An object that provides culture-specific formatting information about s
.
- result
- Byte
When this method returns, contains the result of successfully parsing s
or an undefined value on failure.
Returns
true
if s
was successfully parsed; otherwise, false
.
Applies to
.NET 9 dan versi lain
Produk | Versi |
---|---|
.NET | 7, 8, 9 |
- Source:
- Byte.cs
- Source:
- Byte.cs
Tries to parse a span of UTF-8 characters into a value.
public:
static bool TryParse(ReadOnlySpan<System::Byte> utf8Text, System::Globalization::NumberStyles style, IFormatProvider ^ provider, [Runtime::InteropServices::Out] System::Byte % result) = System::Numerics::INumberBase<System::Byte>::TryParse;
public static bool TryParse (ReadOnlySpan<byte> utf8Text, System.Globalization.NumberStyles style, IFormatProvider? provider, out byte result);
static member TryParse : ReadOnlySpan<byte> * System.Globalization.NumberStyles * IFormatProvider * byte -> bool
Public Shared Function TryParse (utf8Text As ReadOnlySpan(Of Byte), style As NumberStyles, provider As IFormatProvider, ByRef result As Byte) As Boolean
Parameters
- utf8Text
- ReadOnlySpan<Byte>
The span of UTF-8 characters to parse.
- style
- NumberStyles
A bitwise combination of number styles that can be present in utf8Text
.
- provider
- IFormatProvider
An object that provides culture-specific formatting information about utf8Text
.
- result
- Byte
On return, contains the result of successfully parsing utf8Text
or an undefined value on failure.
Returns
true
if utf8Text
was successfully parsed; otherwise, false
.
Applies to
.NET 9 dan .NET 8
Produk | Versi |
---|---|
.NET | 8, 9 |
- Source:
- Byte.cs
- Source:
- Byte.cs
Tries to convert a UTF-8 character span containing the string representation of a number to its 8-bit unsigned integer equivalent.
public:
static bool TryParse(ReadOnlySpan<System::Byte> utf8Text, [Runtime::InteropServices::Out] System::Byte % result);
public static bool TryParse (ReadOnlySpan<byte> utf8Text, out byte result);
static member TryParse : ReadOnlySpan<byte> * byte -> bool
Public Shared Function TryParse (utf8Text As ReadOnlySpan(Of Byte), ByRef result As Byte) As Boolean
Parameters
- utf8Text
- ReadOnlySpan<Byte>
A span containing the UTF-8 characters representing the number to convert.
- result
- Byte
When this method returns, contains the 8-bit unsigned integer value equivalent to the number contained in utf8Text
if the conversion succeeded, or zero if the conversion failed. This parameter is passed uninitialized; any value originally supplied in result will be overwritten.
Returns
true
if utf8Text
was converted successfully; otherwise, false
.
Applies to
.NET 9 dan .NET 8
Produk | Versi |
---|---|
.NET | 8, 9 |
- Source:
- Byte.cs
- Source:
- Byte.cs
- Source:
- Byte.cs
Converts the span representation of a number in a specified style and culture-specific format to its Byte equivalent. A return value indicates whether the conversion succeeded or failed.
public:
static bool TryParse(ReadOnlySpan<char> s, System::Globalization::NumberStyles style, IFormatProvider ^ provider, [Runtime::InteropServices::Out] System::Byte % result);
public:
static bool TryParse(ReadOnlySpan<char> s, System::Globalization::NumberStyles style, IFormatProvider ^ provider, [Runtime::InteropServices::Out] System::Byte % result) = System::Numerics::INumberBase<System::Byte>::TryParse;
public static bool TryParse (ReadOnlySpan<char> s, System.Globalization.NumberStyles style, IFormatProvider? provider, out byte result);
public static bool TryParse (ReadOnlySpan<char> s, System.Globalization.NumberStyles style, IFormatProvider provider, out byte result);
static member TryParse : ReadOnlySpan<char> * System.Globalization.NumberStyles * IFormatProvider * byte -> bool
Public Shared Function TryParse (s As ReadOnlySpan(Of Char), style As NumberStyles, provider As IFormatProvider, ByRef result As Byte) As Boolean
Parameters
- s
- ReadOnlySpan<Char>
A span containing the characters representing the number to convert. The span is interpreted using the Integer style.
- style
- NumberStyles
A bitwise combination of enumeration values that indicates the style elements that can be present in s
. A typical value to specify is Integer.
- provider
- IFormatProvider
An object that supplies culture-specific formatting information about s
. If provider
is null
, the thread current culture is used.
- result
- Byte
When this method returns, contains the 8-bit unsigned integer value equivalent to the number contained in s
if the conversion succeeded, or zero if the conversion failed. The conversion fails if the s
parameter is null
or Empty, is not of the correct format, or represents a number less than Byte.MinValue or greater than Byte.MaxValue. This parameter is passed uninitialized; any value originally supplied in result
will be overwritten.
Returns
true
if s
was converted successfully; otherwise, false
.
Applies to
.NET 9 dan versi lain
Produk | Versi |
---|---|
.NET | Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Standard | 2.1 |
- Source:
- Byte.cs
- Source:
- Byte.cs
- Source:
- Byte.cs
Converts the string representation of a number in a specified style and culture-specific format to its Byte equivalent. A return value indicates whether the conversion succeeded or failed.
public:
static bool TryParse(System::String ^ s, System::Globalization::NumberStyles style, IFormatProvider ^ provider, [Runtime::InteropServices::Out] System::Byte % result);
public:
static bool TryParse(System::String ^ s, System::Globalization::NumberStyles style, IFormatProvider ^ provider, [Runtime::InteropServices::Out] System::Byte % result) = System::Numerics::INumberBase<System::Byte>::TryParse;
public static bool TryParse (string s, System.Globalization.NumberStyles style, IFormatProvider provider, out byte result);
public static bool TryParse (string? s, System.Globalization.NumberStyles style, IFormatProvider? provider, out byte result);
static member TryParse : string * System.Globalization.NumberStyles * IFormatProvider * byte -> bool
Public Shared Function TryParse (s As String, style As NumberStyles, provider As IFormatProvider, ByRef result As Byte) As Boolean
Parameters
- s
- String
A string containing a number to convert. The string is interpreted using the style specified by style
.
- style
- NumberStyles
A bitwise combination of enumeration values that indicates the style elements that can be present in s
. A typical value to specify is Integer.
- provider
- IFormatProvider
An object that supplies culture-specific formatting information about s
. If provider
is null
, the thread current culture is used.
- result
- Byte
When this method returns, contains the 8-bit unsigned integer value equivalent to the number contained in s
if the conversion succeeded, or zero if the conversion failed. The conversion fails if the s
parameter is null
or Empty, is not of the correct format, or represents a number less than Byte.MinValue or greater than Byte.MaxValue. This parameter is passed uninitialized; any value originally supplied in result
will be overwritten.
Returns
true
if s
was converted successfully; otherwise, false
.
Exceptions
style
is not a NumberStyles value.
-or-
style
is not a combination of AllowHexSpecifier and HexNumber values.
Examples
The following example calls the TryParse(String, NumberStyles, IFormatProvider, Byte) method with a number of different string values.
using namespace System;
using namespace System::Globalization;
void CallTryParse(String^ byteString, NumberStyles styles);
void main()
{
String^ byteString;
NumberStyles styles;
byteString = "1024";
styles = NumberStyles::Integer;
CallTryParse(byteString, styles);
byteString = "100.1";
styles = NumberStyles::Integer | NumberStyles::AllowDecimalPoint;
CallTryParse(byteString, styles);
byteString = "100.0";
CallTryParse(byteString, styles);
byteString = "+100";
styles = NumberStyles::Integer | NumberStyles::AllowLeadingSign
| NumberStyles::AllowTrailingSign;
CallTryParse(byteString, styles);
byteString = "-100";
CallTryParse(byteString, styles);
byteString = "000000000000000100";
CallTryParse(byteString, styles);
byteString = "00,100";
styles = NumberStyles::Integer | NumberStyles::AllowThousands;
CallTryParse(byteString, styles);
byteString = "2E+3 ";
styles = NumberStyles::Integer | NumberStyles::AllowExponent;
CallTryParse(byteString, styles);
byteString = "FF";
styles = NumberStyles::HexNumber;
CallTryParse(byteString, styles);
byteString = "0x1F";
CallTryParse(byteString, styles);
}
void CallTryParse(String^ stringToConvert, NumberStyles styles)
{
Byte byteValue;
bool result = Byte::TryParse(stringToConvert, styles,
(IFormatProvider^) nullptr , byteValue);
if (result)
Console::WriteLine("Converted '{0}' to {1}",
stringToConvert, byteValue);
else
Console::WriteLine("Attempted conversion of '{0}' failed.",
stringToConvert);
}
// The example displays the following output:
// Attempted conversion of '1024' failed.
// Attempted conversion of '100.1' failed.
// Converted '100.0' to 100
// Converted '+100' to 100
// Attempted conversion of '-100' failed.
// Converted '000000000000000100' to 100
// Converted '00,100' to 100
// Attempted conversion of '2E+3 ' failed.
// Converted 'FF' to 255
// Attempted conversion of '0x1F' failed.}
using System;
using System.Globalization;
public class ByteConversion2
{
public static void Main()
{
string byteString;
NumberStyles styles;
byteString = "1024";
styles = NumberStyles.Integer;
CallTryParse(byteString, styles);
byteString = "100.1";
styles = NumberStyles.Integer | NumberStyles.AllowDecimalPoint;
CallTryParse(byteString, styles);
byteString = "100.0";
CallTryParse(byteString, styles);
byteString = "+100";
styles = NumberStyles.Integer | NumberStyles.AllowLeadingSign
| NumberStyles.AllowTrailingSign;
CallTryParse(byteString, styles);
byteString = "-100";
CallTryParse(byteString, styles);
byteString = "000000000000000100";
CallTryParse(byteString, styles);
byteString = "00,100";
styles = NumberStyles.Integer | NumberStyles.AllowThousands;
CallTryParse(byteString, styles);
byteString = "2E+3 ";
styles = NumberStyles.Integer | NumberStyles.AllowExponent;
CallTryParse(byteString, styles);
byteString = "FF";
styles = NumberStyles.HexNumber;
CallTryParse(byteString, styles);
byteString = "0x1F";
CallTryParse(byteString, styles);
}
private static void CallTryParse(string stringToConvert, NumberStyles styles)
{
Byte byteValue;
bool result = Byte.TryParse(stringToConvert, styles,
null as IFormatProvider, out byteValue);
if (result)
Console.WriteLine("Converted '{0}' to {1}",
stringToConvert, byteValue);
else
Console.WriteLine("Attempted conversion of '{0}' failed.",
stringToConvert.ToString());
}
}
// The example displays the following output to the console:
// Attempted conversion of '1024' failed.
// Attempted conversion of '100.1' failed.
// Converted '100.0' to 100
// Converted '+100' to 100
// Attempted conversion of '-100' failed.
// Converted '000000000000000100' to 100
// Converted '00,100' to 100
// Attempted conversion of '2E+3 ' failed.
// Converted 'FF' to 255
// Attempted conversion of '0x1F' failed.
open System
open System.Globalization
let callTryParse (stringToConvert: string) (styles: NumberStyles) =
match Byte.TryParse(stringToConvert, styles, null) with
| true, byteValue ->
printfn $"Converted '{stringToConvert}' to {byteValue}"
| _ ->
printfn $"Attempted conversion of '{stringToConvert}' failed."
[<EntryPoint>]
let main _ =
let byteString = "1024"
let styles = NumberStyles.Integer
callTryParse byteString styles
let byteString = "100.1"
let styles = NumberStyles.Integer ||| NumberStyles.AllowDecimalPoint
callTryParse byteString styles
let byteString = "100.0"
callTryParse byteString styles
let byteString = "+100"
let styles = NumberStyles.Integer ||| NumberStyles.AllowLeadingSign ||| NumberStyles.AllowTrailingSign
callTryParse byteString styles
let byteString = "-100"
callTryParse byteString styles
let byteString = "000000000000000100"
callTryParse byteString styles
let byteString = "00,100"
let styles = NumberStyles.Integer ||| NumberStyles.AllowThousands
callTryParse byteString styles
let byteString = "2E+3 "
let styles = NumberStyles.Integer ||| NumberStyles.AllowExponent
callTryParse byteString styles
let byteString = "FF"
let styles = NumberStyles.HexNumber
callTryParse byteString styles
let byteString = "0x1F"
callTryParse byteString styles
0
// The example displays the following output to the console:
// Attempted conversion of '1024' failed.
// Attempted conversion of '100.1' failed.
// Converted '100.0' to 100
// Converted '+100' to 100
// Attempted conversion of '-100' failed.
// Converted '000000000000000100' to 100
// Converted '00,100' to 100
// Attempted conversion of '2E+3 ' failed.
// Converted 'FF' to 255
// Attempted conversion of '0x1F' failed.
Imports System.Globalization
Module ByteConversion2
Public Sub Main()
Dim byteString As String
Dim styles As NumberStyles
byteString = "1024"
styles = NumberStyles.Integer
CallTryParse(byteString, styles)
byteString = "100.1"
styles = NumberStyles.Integer Or NumberStyles.AllowDecimalPoint
CallTryParse(byteString, styles)
byteString = "100.0"
CallTryParse(byteString, styles)
byteString = "+100"
styles = NumberStyles.Integer Or NumberStyles.AllowLeadingSign _
Or NumberStyles.AllowTrailingSign
CallTryParse(byteString, styles)
byteString = "-100"
CallTryParse(byteString, styles)
byteString = "000000000000000100"
CallTryParse(byteString, styles)
byteString = "00,100"
styles = NumberStyles.Integer Or NumberStyles.AllowThousands
CallTryParse(byteString, styles)
byteString = "2E+3 "
styles = NumberStyles.Integer Or NumberStyles.AllowExponent
CallTryParse(byteString, styles)
byteString = "FF"
styles = NumberStyles.HexNumber
CallTryParse(byteString, styles)
byteString = "0x1F"
CallTryParse(byteString, styles)
End Sub
Private Sub CallTryParse(stringToConvert As String, styles As NumberStyles)
Dim byteValue As Byte
Dim result As Boolean = Byte.TryParse(stringToConvert, styles, Nothing, _
byteValue)
If result Then
Console.WriteLine("Converted '{0}' to {1}", _
stringToConvert, byteValue)
Else
If stringToConvert Is Nothing Then stringToConvert = ""
Console.WriteLine("Attempted conversion of '{0}' failed.", _
stringToConvert.ToString())
End If
End Sub
End Module
' The example displays the following output to the console:
' Attempted conversion of '1024' failed.
' Attempted conversion of '100.1' failed.
' Converted '100.0' to 100
' Converted '+100' to 100
' Attempted conversion of '-100' failed.
' Converted '000000000000000100' to 100
' Converted '00,100' to 100
' Attempted conversion of '2E+3 ' failed.
' Converted 'FF' to 255
' Attempted conversion of '0x1F' failed.
Remarks
The TryParse method is like the Parse method, except the TryParse method does not throw an exception if the conversion fails.
The s
parameter is parsed using the formatting information in a NumberFormatInfo object supplied by the provider
parameter.
The style parameter defines the style elements (such as white space or the positive sign) that are allowed in the s
parameter for the parse operation to succeed. It must be a combination of bit flags from the NumberStyles enumeration. Depending on the value of style
, the s
parameter may include the following elements:
[ws][$][sign]digits[.fractional_digits][e[sign]digits][ws]
Or, if the style
parameter includes AllowHexSpecifier:
[ws]hexdigits[ws]
Elements in square brackets ( [ and ] ) are optional. The following table describes each element.
Element | Description |
---|---|
ws | Optional white space. White space can appear at the beginning of s if style includes the NumberStyles.AllowLeadingWhite flag, or at the end of s if style includes the NumberStyles.AllowTrailingWhite flag. |
$ | A culture-specific currency symbol. Its position in the string is defined by the NumberFormatInfo.CurrencyPositivePattern property of the NumberFormatInfo object returned by the GetFormat method of the provider parameter. The currency symbol can appear in s if style includes the NumberStyles.AllowCurrencySymbol flag. |
sign | An optional positive sign. (The parse operation fails if a negative sign is present in s .) The sign can appear at the beginning of s if style includes the NumberStyles.AllowLeadingSign flag, or at the end of s if style includes the NumberStyles.AllowTrailingSign flag. |
digits | A sequence of digits from 0 through 9. |
. | A culture-specific decimal point symbol. The decimal point symbol of the culture specified by provider can appear in s if style includes the NumberStyles.AllowDecimalPoint flag. |
fractional_digits | One or more occurrences of the digit 0. Fractional digits can appear in s only if style includes the NumberStyles.AllowDecimalPoint flag. |
e | The e or E character, which indicates that the value is represented in exponential notation. The s parameter can represent a number in exponential notation if style includes the NumberStyles.AllowExponent flag. |
hexdigits | A sequence of hexadecimal digits from 0 through f, or 0 through F. |
Nota
Any terminating NUL (U+0000) characters in s
are ignored by the parsing operation, regardless of the value of the style
argument.
A string with decimal digits only (which corresponds to the NumberStyles.None style) always parses successfully. Most of the remaining NumberStyles members control elements that may be but are not required to be present in this input string. The following table indicates how individual NumberStyles members affect the elements that may be present in s
.
Non-composite NumberStyles values | Elements permitted in s in addition to digits |
---|---|
NumberStyles.None | Decimal digits only. |
NumberStyles.AllowDecimalPoint | The . and fractional_digits elements. However, fractional_digits must consist of only one or more 0 digits or the method returns false . |
NumberStyles.AllowExponent | The s parameter can also use exponential notation. If s represents a number in exponential notation, it must represent an integer within the range of the Byte data type without a non-zero, fractional component. |
NumberStyles.AllowLeadingWhite | The ws element at the beginning of s . |
NumberStyles.AllowTrailingWhite | The ws element at the end of s . |
NumberStyles.AllowLeadingSign | A positive sign can appear before digits. |
NumberStyles.AllowTrailingSign | A positive sign can appear after digits. |
NumberStyles.AllowParentheses | Although this flag is supported, the method returns false if parentheses are present in s . |
NumberStyles.AllowThousands | Although the group separator symbol can appear in s , it can be preceded by only one or more 0 digits. |
NumberStyles.AllowCurrencySymbol | The $ element. |
If the NumberStyles.AllowHexSpecifier flag is used, s
must be a hexadecimal value without a prefix. For example, "F3" parses successfully, but "0xF3" does not. The only other flags that can be present in style
are NumberStyles.AllowLeadingWhite and NumberStyles.AllowTrailingWhite. (The NumberStyles enumeration has a composite number style, NumberStyles.HexNumber, that includes both white space flags.)
The provider
parameter is an IFormatProvider implementation, such as a CultureInfo object or a NumberFormatInfo object, whose GetFormat method returns a NumberFormatInfo object. The NumberFormatInfo object provides culture-specific information about the format of s
.
See also
- ToString()
- MaxValue
- MinValue
- NumberStyles
- NumberFormatInfo
- IFormatProvider
- Parsing Numeric Strings in .NET
Applies to
.NET 9 dan versi lain
Produk | Versi |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 2.0, 2.1 |
UWP | 10.0 |
.NET maklum balas
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