Convert.ToSingle Method (String, IFormatProvider)
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Converts the specified String representation of a number to an equivalent single-precision floating point number using the specified culture-specific formatting information.
Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Syntax
'Declaration
Public Shared Function ToSingle ( _
value As String, _
provider As IFormatProvider _
) As Single
public static float ToSingle(
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.Single
A single-precision floating point number equivalent to the value of value.
-or-
Zero if value is nulla null reference (Nothing in Visual Basic).
Exceptions
| Exception | Condition |
|---|---|
| FormatException | value is not a number in a valid format. |
| OverflowException | value represents a number less than MinValue or greater than MaxValue. |
Remarks
The return value is the result of invoking the Single.Parse method on value.
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 Single.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 Single values with the ToSingle method, using an IFormatProvider object.
' Example of the Convert.ToSingle( String ) and
' Convert.ToSingle( String, IFormatProvider ) methods.
Imports System.Globalization
Module Example
Dim formatter As String = "{0,-22}{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()
GetExceptionType = exceptionType.Substring( _
exceptionType.LastIndexOf("."c) + 1)
End Function
Sub ConvertToSingle(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 Single without a format provider.
Try
defaultValue = Convert.ToSingle(numericStr)
Catch ex As Exception
defaultValue = GetExceptionType(ex)
End Try
' Convert numericStr to Single with a format provider.
Try
providerValue = Convert.ToSingle(numericStr, provider)
Catch ex As Exception
providerValue = GetExceptionType(ex)
End Try
outputBlock.Text &= String.Format(formatter, 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()
provider.NumberDecimalSeparator = ","
provider.NumberGroupSeparator = "."
provider.NumberGroupSizes = New Integer() {3}
outputBlock.Text &= String.Format("This example of" & vbCrLf & _
" Convert.ToSingle( String ) and " & vbCrLf & _
" Convert.ToSingle( String, IFormatProvider ) " & _
vbCrLf & "generates the " & _
"following output when run in the [{0}] culture.", _
CultureInfo.CurrentCulture.Name) & vbCrLf
outputBlock.Text &= String.Format(vbCrLf & _
"Several strings are converted to Single values, " & _
"using " & vbCrLf & "default formatting " & _
"and a NumberFormatInfo object." & vbCrLf) & vbCrLf
outputBlock.Text &= String.Format(formatter, "String to convert", _
"Default/exception", "Provider/exception") & vbCrLf
outputBlock.Text &= String.Format(formatter, "-----------------", _
"-----------------", "------------------") & vbCrLf
' Convert strings, with and without an IFormatProvider.
ConvertToSingle(outputBlock, "1234567", provider)
ConvertToSingle(outputBlock, "1234.567", provider)
ConvertToSingle(outputBlock, "1234,567", provider)
ConvertToSingle(outputBlock, "12,345.67", provider)
ConvertToSingle(outputBlock, "12.345,67", provider)
ConvertToSingle(outputBlock, "1,234,567.89", provider)
ConvertToSingle(outputBlock, "1.234.567,89", provider)
End Sub
End Module
' This example of
' Convert.ToSingle( String ) and
' Convert.ToSingle( String, IFormatProvider )
' generates the following output when run in the [en-US] culture.
'
' Several strings are converted to Single values, using
' default formatting and a NumberFormatInfo object.
'
' String to convert Default/exception Provider/exception
' ----------------- ----------------- ------------------
' 1234567 1234567 1234567
' 1234.567 1234.567 1234567
' 1234,567 1234567 1234.567
' 12,345.67 12345.67 FormatException
' 12.345,67 FormatException 12345.67
' 1,234,567.89 1234568 FormatException
' 1.234.567,89 FormatException 1234568
// Example of the Convert.ToSingle( String ) and
// Convert.ToSingle( String, IFormatProvider ) methods.
using System;
using System.Globalization;
class Example
{
static string formatter = "{0,-22}{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 ConvertToSingle(System.Windows.Controls.TextBlock outputBlock, string numericStr,
IFormatProvider provider)
{
object defaultValue;
object providerValue;
// Convert numericStr to float without a format provider.
try
{
defaultValue = Convert.ToSingle(numericStr);
}
catch (Exception ex)
{
defaultValue = GetExceptionType(ex);
}
// Convert numericStr to float with a format provider.
try
{
providerValue = Convert.ToSingle(numericStr, provider);
}
catch (Exception ex)
{
providerValue = GetExceptionType(ex);
}
outputBlock.Text += String.Format(formatter, 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();
provider.NumberDecimalSeparator = ",";
provider.NumberGroupSeparator = ".";
provider.NumberGroupSizes = new int[] { 3 };
outputBlock.Text += String.Format(
"This example of\n Convert.ToSingle( String ) and \n" +
" Convert.ToSingle( String, IFormatProvider ) \n" +
"generates the following output when run in the " +
"[{0}] culture.",
CultureInfo.CurrentCulture.Name) + "\n";
outputBlock.Text += String.Format("\nSeveral " +
"strings are converted to float values, using \n" +
"default formatting and a NumberFormatInfo object.\n") + "\n";
outputBlock.Text += String.Format(formatter, "String to convert",
"Default/exception", "Provider/exception") + "\n";
outputBlock.Text += String.Format(formatter, "-----------------",
"-----------------", "------------------") + "\n";
// Convert strings, with and without an IFormatProvider.
ConvertToSingle(outputBlock, "1234567", provider);
ConvertToSingle(outputBlock, "1234.567", provider);
ConvertToSingle(outputBlock, "1234,567", provider);
ConvertToSingle(outputBlock, "12,345.67", provider);
ConvertToSingle(outputBlock, "12.345,67", provider);
ConvertToSingle(outputBlock, "1,234,567.89", provider);
ConvertToSingle(outputBlock, "1.234.567,89", provider);
}
}
/*
This example of
Convert.ToSingle( String ) and
Convert.ToSingle( String, IFormatProvider )
generates the following output when run in the [en-US] culture.
Several strings are converted to float values, using
default formatting and a NumberFormatInfo object.
String to convert Default/exception Provider/exception
----------------- ----------------- ------------------
1234567 1234567 1234567
1234.567 1234.567 1234567
1234,567 1234567 1234.567
12,345.67 12345.67 FormatException
12.345,67 FormatException 12345.67
1,234,567.89 1234568 FormatException
1.234.567,89 FormatException 1234568
*/
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.