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Int64.Parse Method (String, IFormatProvider)

Updated: July 2008

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

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

public static long Parse(
	string s,
	IFormatProvider provider
)

Parameters

s
Type: System.String

A string containing a number to convert.

provider
Type: System.IFormatProvider

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

Return Value

Type: System.Int64
A 64-bit signed integer equivalent to the number specified in s.

ExceptionCondition
ArgumentNullException

s is null.

FormatException

s is not in the correct format.

OverflowException

s 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 an Int64 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, and other items are as follows.

ws

An optional white space.

sign

An optional sign.

digits

A sequence of digits ranging from 0 to 9.

The s parameter is interpreted using the NumberStyles.Integer style. In addition to decimal digits, only leading and trailing spaces together with a leading sign are allowed. To explicitly define the style elements that can be present in s, use the Int64.Parse(String, NumberStyles, IFormatProvider) method.

The provider parameter is an IFormatProvider implementation, such as a NumberFormatInfo or CultureInfo object. The provider parameter supplies culture-specific information about the format of s. 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 an Int64 value.

protected void OkToLong_Click(object sender, EventArgs e)
{
   string locale;
   long 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 = Int64.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

July 2008

Added detail about the s parameter.

Information enhancement.

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