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Convert.ToSingle Method (String, IFormatProvider)

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)

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 null.

ExceptionCondition
FormatException

value is not a number in a valid format.

OverflowException

value represents a number less than MinValue or greater than MaxValue.

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 null, 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.

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.
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
*/


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

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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