Convert.ToByte Method (String, IFormatProvider)
Microsoft Silverlight will reach end of support after October 2021. Learn more.
Converts the specified String representation of a number to an equivalent 8-bit unsigned integer using specified culture-specific formatting information.
Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Syntax
'Declaration
Public Shared Function ToByte ( _
value As String, _
provider As IFormatProvider _
) As Byte
public static byte ToByte(
string value,
IFormatProvider provider
)
Parameters
- value
Type: System.String
A String containing a number to convert.
- provider
Type: System.IFormatProvider
An IFormatProvider interface implementation that supplies culture-specific formatting information.
Return Value
Type: System.Byte
An 8-bit signed integer equivalent to the value of value.
-or-
Zero if value is nulla null reference (Nothing in Visual Basic).
Exceptions
| Exception | Condition |
|---|---|
| FormatException | value does not consist of an optional sign followed by a sequence of digits (zero through nine). |
| OverflowException | value represents a number less than MinValue or greater than MaxValue. |
Remarks
provider is an IFormatProvider instance that obtains a NumberFormatInfo object. The NumberFormatInfo object provides culture-specific information about the format of value. If provider is nulla null reference (Nothing in Visual Basic), the NumberFormatInfo for the current culture is used.
If you prefer not to handle an exception if the conversion fails, you can call the Byte.TryParse method instead. It returns a Boolean value that indicates whether the conversion succeeded or failed.
Examples
The following code example converts String representations of unsigned Byte values with the ToByte method, using an IFormatProvider object.
' Example of the Convert.ToByte( String ) and
' Convert.ToByte( String, IFormatProvider ) methods.
Imports System.Globalization
Module Example
Dim format As String = "{0,-20}{1,-20}{2}"
' Get the exception type name; remove the namespace prefix.
Function GetExceptionType(ByVal ex As Exception) As String
Dim exceptionType As String = ex.GetType().ToString()
Return exceptionType.Substring( _
exceptionType.LastIndexOf("."c) + 1)
End Function
Sub ConvertToByte(ByVal outputBlock As System.Windows.Controls.TextBlock, ByVal numericStr As String, _
ByVal provider As IFormatProvider)
Dim defaultValue As Object
Dim providerValue As Object
' Convert numericStr to Byte without a format provider.
Try
defaultValue = Convert.ToByte(numericStr)
Catch ex As Exception
defaultValue = GetExceptionType(ex)
End Try
' Convert numericStr to Byte with a format provider.
Try
providerValue = Convert.ToByte(numericStr, provider)
Catch ex As Exception
providerValue = GetExceptionType(ex)
End Try
outputBlock.Text &= String.Format(format, numericStr, _
defaultValue, providerValue) & vbCrLf
End Sub
Public Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
' Create a NumberFormatInfo object and set several of its
' properties that apply to numbers.
Dim provider As NumberFormatInfo = New NumberFormatInfo()
' These properties affect the conversion.
provider.PositiveSign = "pos "
provider.NegativeSign = "neg "
' These properties do not affect the conversion.
' The input string cannot have decimal and group separators.
provider.NumberDecimalSeparator = "."
outputBlock.Text &= String.Format("This example of" & vbCrLf & _
" Convert.ToByte( String ) and " & vbCrLf & _
" Convert.ToByte( String, IFormatProvider ) " & _
vbCrLf & "generates the following output. It " & _
"converts several strings to " & vbCrLf & "Byte " & _
"values, using default formatting " & _
"or a NumberFormatInfo object." & vbCrLf) & vbCrLf
outputBlock.Text &= String.Format(format, "String to convert", _
"Default/exception", "Provider/exception") & vbCrLf
outputBlock.Text &= String.Format(format, "-----------------", _
"-----------------", "------------------") & vbCrLf
' Convert strings, with and without an IFormatProvider.
ConvertToByte(outputBlock, "234", provider)
ConvertToByte(outputBlock, "+234", provider)
ConvertToByte(outputBlock, "pos 234", provider)
ConvertToByte(outputBlock, "234.", provider)
ConvertToByte(outputBlock, "255", provider)
ConvertToByte(outputBlock, "256", provider)
ConvertToByte(outputBlock, "-1", provider)
End Sub
End Module
' This example of
' Convert.ToByte( String ) and
' Convert.ToByte( String, IFormatProvider )
' generates the following output. It converts several strings to
' Byte values, using default formatting or a NumberFormatInfo object.
'
' String to convert Default/exception Provider/exception
' ----------------- ----------------- ------------------
' 234 234 234
' +234 234 FormatException
' pos 234 FormatException 234
' 234. FormatException FormatException
' 255 255 255
' 256 OverflowException OverflowException
' -1 OverflowException FormatException
// Example of the Convert.ToByte( string ) and
// Convert.ToByte( string, IFormatProvider ) methods.
using System;
using System.Globalization;
class Example
{
static string format = "{0,-20}{1,-20}{2}";
// Get the exception type name; remove the namespace prefix.
static string GetExceptionType(Exception ex)
{
string exceptionType = ex.GetType().ToString();
return exceptionType.Substring(
exceptionType.LastIndexOf('.') + 1);
}
static void ConvertToByte(System.Windows.Controls.TextBlock outputBlock, string numericStr,
IFormatProvider provider)
{
object defaultValue;
object providerValue;
// Convert numericStr to Byte without a format provider.
try
{
defaultValue = Convert.ToByte(numericStr);
}
catch (Exception ex)
{
defaultValue = GetExceptionType(ex);
}
// Convert numericStr to Byte with a format provider.
try
{
providerValue = Convert.ToByte(numericStr, provider);
}
catch (Exception ex)
{
providerValue = GetExceptionType(ex);
}
outputBlock.Text += String.Format(format, numericStr,
defaultValue, providerValue) + "\n";
}
public static void Demo(System.Windows.Controls.TextBlock outputBlock)
{
// Create a NumberFormatInfo object and set several of its
// properties that apply to numbers.
NumberFormatInfo provider = new NumberFormatInfo();
// These properties affect the conversion.
provider.NegativeSign = "neg ";
provider.PositiveSign = "pos ";
// These properties do not affect the conversion.
// The input string cannot have decimal and group separators.
provider.NumberDecimalSeparator = ".";
outputBlock.Text += String.Format("This example of\n" +
" Convert.ToByte( string ) and \n" +
" Convert.ToByte( string, IFormatProvider ) " +
"\ngenerates the following output. It converts " +
"several strings to \nbyte values, using " +
"default formatting or a NumberFormatInfo object.\n") + "\n";
outputBlock.Text += String.Format(format, "String to convert",
"Default/exception", "Provider/exception") + "\n";
outputBlock.Text += String.Format(format, "-----------------",
"-----------------", "------------------") + "\n";
// Convert strings, with and without an IFormatProvider.
ConvertToByte(outputBlock, "234", provider);
ConvertToByte(outputBlock, "+234", provider);
ConvertToByte(outputBlock, "pos 234", provider);
ConvertToByte(outputBlock, "234.", provider);
ConvertToByte(outputBlock, "255", provider);
ConvertToByte(outputBlock, "256", provider);
ConvertToByte(outputBlock, "-1", provider);
}
}
/*
This example of
Convert.ToByte( string ) and
Convert.ToByte( string, IFormatProvider )
generates the following output. It converts several strings to
byte values, using default formatting or a NumberFormatInfo object.
String to convert Default/exception Provider/exception
----------------- ----------------- ------------------
234 234 234
+234 234 FormatException
pos 234 FormatException 234
234. FormatException FormatException
255 255 255
256 OverflowException OverflowException
-1 OverflowException FormatException
*/
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.