Byte.TryParse Method

Reference

Definition

Namespace:: System

Assembly:: System.Runtime.dll

Assembly:: netstandard.dll

Assembly:: mscorlib.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Tries to convert the string representation of a number to its Byte equivalent, and returns a value that indicates whether the conversion succeeded.

Overloads

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.

TryParse(ReadOnlySpan<Byte>, IFormatProvider, Byte)

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

Boolean

true if utf8Text was successfully parsed; otherwise, false.

Applies to

TryParse(ReadOnlySpan<Char>, Byte)

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

Boolean

true if s was converted successfully; otherwise, false.

Applies to

TryParse(String, Byte)

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

Returns

Boolean

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.

Applies to

TryParse(ReadOnlySpan<Char>, IFormatProvider, Byte)

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

Boolean

true if s was successfully parsed; otherwise, false.

Applies to

TryParse(String, IFormatProvider, Byte)

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

Boolean

true if s was successfully parsed; otherwise, false.

Applies to

TryParse(ReadOnlySpan<Byte>, NumberStyles, IFormatProvider, Byte)

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

Boolean

true if utf8Text was successfully parsed; otherwise, false.

Applies to

TryParse(ReadOnlySpan<Byte>, Byte)

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

Boolean

true if utf8Text was converted successfully; otherwise, false.

Applies to

TryParse(ReadOnlySpan<Char>, NumberStyles, IFormatProvider, Byte)

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

Boolean

true if s was converted successfully; otherwise, false.

Applies to

TryParse(String, NumberStyles, IFormatProvider, Byte)

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

Returns

Boolean

true if s was converted successfully; otherwise, false.

Exceptions

ArgumentException

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.

Note

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.

Applies to

Κοινή χρήση μέσω

Byte.TryParse Method

Definition

Overloads

TryParse(ReadOnlySpan<Byte>, IFormatProvider, Byte)

Parameters

Returns

Applies to

TryParse(ReadOnlySpan<Char>, Byte)

Parameters

Returns

Applies to

TryParse(String, Byte)

Parameters

Returns

Examples

Remarks

See also

Applies to

TryParse(ReadOnlySpan<Char>, IFormatProvider, Byte)

Parameters

Returns

Applies to

TryParse(String, IFormatProvider, Byte)

Parameters

Returns

Applies to

TryParse(ReadOnlySpan<Byte>, NumberStyles, IFormatProvider, Byte)

Parameters

Returns

Applies to

TryParse(ReadOnlySpan<Byte>, Byte)

Parameters

Returns

Applies to

TryParse(ReadOnlySpan<Char>, NumberStyles, IFormatProvider, Byte)

Parameters

Returns

Applies to

TryParse(String, NumberStyles, IFormatProvider, Byte)

Parameters

Returns

Exceptions

Examples

Remarks

See also

Applies to

Πρόσθετοι πόροι