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Byte.TryParse Method (String, Byte%)
Microsoft Silverlight will reach end of support after October 2021. Learn more.
Tries to convert the string representation of a number to its Byte equivalent, and returns a value that indicates whether the conversion succeeded.
Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Syntax
'Declaration
Public Shared Function TryParse ( _
s As String, _
<OutAttribute> ByRef result As Byte _
) As Boolean
public static bool TryParse(
string s,
out byte result
)
Parameters
- s
Type: System.String
A string that contains a number to convert. The string is interpreted using the Integer style.
- result
Type: System.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.
Return Value
Type: System.Boolean
true if s was converted successfully; otherwise, false.
Remarks
The conversion fails and the method returns false if the s parameter is not in the correct format, if it is nulla null reference (Nothing in Visual Basic), 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.
Examples
The following example calls the TryParse(String, Byte%) method with a number of different string values.
Module Example
Public Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
Dim byteString As String = Nothing
CallTryParse(outputBlock, byteString)
byteString = String.Empty
CallTryParse(outputBlock, byteString)
byteString = "1024"
CallTryParse(outputBlock, byteString)
byteString = "100.1"
CallTryParse(outputBlock, byteString)
byteString = "100"
CallTryParse(outputBlock, byteString)
byteString = "+100"
CallTryParse(outputBlock, byteString)
byteString = "-100"
CallTryParse(outputBlock, byteString)
byteString = "000000000000000100"
CallTryParse(outputBlock, byteString)
byteString = "00,100"
CallTryParse(outputBlock, byteString)
byteString = " 20 "
CallTryParse(outputBlock, byteString)
byteString = "FF"
CallTryParse(outputBlock, byteString)
byteString = "0x1F"
CallTryParse(outputBlock, byteString)
End Sub
Private Sub CallTryParse(ByVal outputBlock As System.Windows.Controls.TextBlock, ByVal stringToConvert As String)
Dim byteValue As Byte
Dim result As Boolean = Byte.TryParse(stringToConvert, byteValue)
If result Then
outputBlock.Text += String.Format("Converted '{0}' to {1}", _
stringToConvert, byteValue) + vbCrLf
Else
If stringToConvert Is Nothing Then stringToConvert = ""
outputBlock.Text += String.Format("Attempted conversion of '{0}' failed.", _
stringToConvert.ToString()) + vbCrLf
End If
End Sub
End Module
' 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 Example
{
public static void Demo(System.Windows.Controls.TextBlock outputBlock)
{
string byteString = null;
CallTryParse(outputBlock, byteString);
byteString = String.Empty;
CallTryParse(outputBlock, byteString);
byteString = "1024";
CallTryParse(outputBlock, byteString);
byteString = "100.1";
CallTryParse(outputBlock, byteString);
byteString = "100";
CallTryParse(outputBlock, byteString);
byteString = "+100";
CallTryParse(outputBlock, byteString);
byteString = "-100";
CallTryParse(outputBlock, byteString);
byteString = "000000000000000100";
CallTryParse(outputBlock, byteString);
byteString = "00,100";
CallTryParse(outputBlock, byteString);
byteString = " 20 ";
CallTryParse(outputBlock, byteString);
byteString = "FF";
CallTryParse(outputBlock, byteString);
byteString = "0x1F";
CallTryParse(outputBlock, byteString);
}
private static void CallTryParse(System.Windows.Controls.TextBlock outputBlock, string stringToConvert)
{
byte byteValue;
bool result = Byte.TryParse(stringToConvert, out byteValue);
if (result)
{
outputBlock.Text += String.Format("Converted '{0}' to {1}",
stringToConvert, byteValue) + "\n";
}
else
{
if (stringToConvert == null) stringToConvert = "";
outputBlock.Text += String.Format("Attempted conversion of '{0}' failed.",
stringToConvert.ToString()) + "\n";
}
}
}
// 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.
Version Information
Silverlight
Supported in: 5, 4, 3
Silverlight for Windows Phone
Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0
XNA Framework
Supported in: Xbox 360, Windows Phone OS 7.0
Platforms
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.