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UInt64.Parse Method (String, IFormatProvider)

Updated: September 2009

Converts the string representation of a number in a specified culture-specific format to its 64-bit unsigned integer equivalent.

This API is not CLS-compliant. The CLS-compliant alternative is Parse(String).

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)

[CLSCompliantAttribute(false)]
public static ulong Parse(
	string s,
	IFormatProvider provider
)

Parameters

s
Type: System.String

A string that represents the number to convert.

provider
Type: System.IFormatProvider

An object that supplies culture-specific formatting information about s.

Return Value

Type: System.UInt64
A 64-bit unsigned integer equivalent to the number specified in s.

ExceptionCondition
ArgumentNullException

The s parameter is null.

FormatException

The s parameter is not in the correct style.

OverflowException

The s parameter represents a number less than MinValue or greater than MaxValue.

This overload of the Parse(String, IFormatProvider) method is typically used to convert text that can be formatted in a variety of ways to a UInt64 value. For example, it can be used to convert the text entered by a user into an HTML text box to a numeric value.

The s parameter contains a number of the form:

[ws][sign]digits[ws]

Items in square brackets ([ and ]) are optional. The following table describes each element.

Element

Description

ws

Optional white space.

sign

An optional positive sign, or a negative sign if s represents the value zero.

digits

A sequence of digits ranging from 0 to 9.

The s parameter is interpreted using the NumberStyles.Integer style. In addition to the unsigned integer value's decimal digits, only leading and trailing spaces along with a leading sign is allowed. (If the negative sign is present, s must represent a value of zero, 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 Parse(String, NumberStyles, IFormatProvider) method.

The provider parameter is an IFormatProvider implementation whose GetFormat method returns a NumberFormatInfo object that provides culture-specific information about the format of s. There are three ways to use the provider parameter to supply custom formatting information to the parse operation:

  • You can pass the actual NumberFormatInfo object that provides formatting information. (Its implementation of GetFormat simply returns itself.)

  • You can pass a CultureInfo object that specifies the culture whose formatting is to be used. Its NumberFormat property provides formatting information.

  • You can pass a custom IFormatProvider implementation. Its GetFormat method must instantiate and return the NumberFormatInfo object that provides formatting information.

If provider is null, the NumberFormatInfo for the current culture is used.

The following example is the button click event handler of a Web form. It uses the array returned by the HttpRequest.UserLanguages property to determine the user's locale. It then instantiates a CultureInfo object that corresponds to that locale. The NumberFormatInfo object that belongs to that CultureInfo object is then passed to the Parse(String, IFormatProvider) method to convert the user's input to a UInt64 value.

protected void OkToSingle_Click(object sender, EventArgs e)
{
   string locale;
   float number;
   CultureInfo culture; 

   // Return if string is empty 
   if (String.IsNullOrEmpty(this.inputNumber.Text))
      return;

   // Get locale of web request to determine possible format of number 
   if (Request.UserLanguages.Length == 0)
      return;
   locale = Request.UserLanguages[0];
   if (String.IsNullOrEmpty(locale))
      return; 

   // Instantiate CultureInfo object for the user's locale
   culture = new CultureInfo(locale);

   // Convert user input from a string to a number 
   try
   {
      number = Single.Parse(this.inputNumber.Text, culture.NumberFormat);
   }
   catch (FormatException)
   {
      return;
   }
   catch (Exception)
   {
      return;
   }
   // Output number to label on web form 
   this.outputNumber.Text = "Number is " + number.ToString();
}

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

Date

History

Reason

September 2009

Revised extensively.

Information enhancement.

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