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UInt16.Parse Method (String, IFormatProvider)

Updated: August 2009

Converts the string representation of a number in a specified culture-specific format to its 16-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 ushort 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.UInt16
A 16-bit unsigned 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 UInt16.MinValue or greater than UInt16.MaxValue.

The s parameter contains a number of the form:

[ws][sign]digits[ws]

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

Element

Description

ws

Optional white space.

sign

An optional positive sign.

digits

A sequence of digits ranging from 0 to 9.

The s parameter is interpreted using the NumberStyles.Integer style. In addition to the byte 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 instantiates a custom culture that uses two plus signs (++) as its positive sign. It then calls the Parse(String, IFormatProvider) method to parse an array of strings by using CultureInfo objects that represent both this custom culture and the invariant culture.


Imports System.Globalization

Module Example
   Public Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
      Dim values() As String = {" 214 ", "1,064", "(0)", "1241+", " + 214 ", " +214 ", "2153.0", "1e03", "1300.0e-2"}
      Dim whitespace As NumberStyles = NumberStyles.AllowLeadingWhite Or NumberStyles.AllowTrailingWhite
      Dim styles() As NumberStyles = {NumberStyles.None, _
                                       whitespace, _
                                       NumberStyles.AllowLeadingSign Or NumberStyles.AllowTrailingSign Or whitespace, _
                                       NumberStyles.AllowThousands Or NumberStyles.AllowCurrencySymbol, _
                                       NumberStyles.AllowExponent Or NumberStyles.AllowDecimalPoint}

      ' Attempt to convert each number using each style combination.
      For Each value As String In values
         outputBlock.Text += String.Format("Attempting to convert '{0}':", value) & vbCrLf
         For Each style As NumberStyles In styles
            Try
               Dim number As UShort = UInt16.Parse(value, style)
               outputBlock.Text += String.Format("   {0}: {1}", style, number) & vbCrLf
            Catch e As FormatException
               outputBlock.Text += String.Format("   {0}: Bad Format", style) & vbCrLf
            End Try
         Next
         outputBlock.Text &= vbCrLf
      Next
   End Sub
End Module
' The example displays the following output:
'    Attempting to convert ' 214 ':
'       None: Bad Format
'       AllowLeadingWhite, AllowTrailingWhite: 214
'       Integer, AllowTrailingSign: 214
'       AllowThousands, AllowCurrencySymbol: Bad Format
'       AllowDecimalPoint, AllowExponent: Bad Format
'    
'    Attempting to convert '1,064':
'       None: Bad Format
'       AllowLeadingWhite, AllowTrailingWhite: Bad Format
'       Integer, AllowTrailingSign: Bad Format
'       AllowThousands, AllowCurrencySymbol: 1064
'       AllowDecimalPoint, AllowExponent: Bad Format
'    
'    Attempting to convert '(0)':
'       None: Bad Format
'       AllowLeadingWhite, AllowTrailingWhite: Bad Format
'       Integer, AllowTrailingSign: Bad Format
'       AllowThousands, AllowCurrencySymbol: Bad Format
'       AllowDecimalPoint, AllowExponent: Bad Format
'    
'    Attempting to convert '1241+':
'       None: Bad Format
'       AllowLeadingWhite, AllowTrailingWhite: Bad Format
'       Integer, AllowTrailingSign: 1241
'       AllowThousands, AllowCurrencySymbol: Bad Format
'       AllowDecimalPoint, AllowExponent: Bad Format
'    
'    Attempting to convert ' + 214 ':
'       None: Bad Format
'       AllowLeadingWhite, AllowTrailingWhite: Bad Format
'       Integer, AllowTrailingSign: Bad Format
'       AllowThousands, AllowCurrencySymbol: Bad Format
'       AllowDecimalPoint, AllowExponent: Bad Format
'    
'    Attempting to convert ' +214 ':
'       None: Bad Format
'       AllowLeadingWhite, AllowTrailingWhite: Bad Format
'       Integer, AllowTrailingSign: 214
'       AllowThousands, AllowCurrencySymbol: Bad Format
'       AllowDecimalPoint, AllowExponent: Bad Format
'    
'    Attempting to convert '2153.0':
'       None: Bad Format
'       AllowLeadingWhite, AllowTrailingWhite: Bad Format
'       Integer, AllowTrailingSign: Bad Format
'       AllowThousands, AllowCurrencySymbol: Bad Format
'       AllowDecimalPoint, AllowExponent: 2153
'    
'    Attempting to convert '1e03':
'       None: Bad Format
'       AllowLeadingWhite, AllowTrailingWhite: Bad Format
'       Integer, AllowTrailingSign: Bad Format
'       AllowThousands, AllowCurrencySymbol: Bad Format
'       AllowDecimalPoint, AllowExponent: 1000
'    
'    Attempting to convert '1300.0e-2':
'       None: Bad Format
'       AllowLeadingWhite, AllowTrailingWhite: Bad Format
'       Integer, AllowTrailingSign: Bad Format
'       AllowThousands, AllowCurrencySymbol: Bad Format
'       AllowDecimalPoint, AllowExponent: 13



using System;
using System.Globalization;

public class Example
{
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      string[] values = { " 214 ", "1,064", "(0)", "1241+", " + 214 ", " +214 ", "2153.0", "1e03", "1300.0e-2" };
      NumberStyles whitespace = NumberStyles.AllowLeadingWhite | NumberStyles.AllowTrailingWhite;
      NumberStyles[] styles = { NumberStyles.None, whitespace, 
                                NumberStyles.AllowLeadingSign | NumberStyles.AllowTrailingSign | whitespace, 
                                NumberStyles.AllowThousands | NumberStyles.AllowCurrencySymbol, 
                                NumberStyles.AllowExponent | NumberStyles.AllowDecimalPoint };

      // Attempt to convert each number using each style combination.
      foreach (string value in values)
      {
         outputBlock.Text += String.Format("Attempting to convert '{0}':", value) + "\n";
         foreach (NumberStyles style in styles)
         {
            try
            {
               ushort number = UInt16.Parse(value, style);
               outputBlock.Text += String.Format("   {0}: {1}", style, number) + "\n";
            }
            catch (FormatException)
            {
               outputBlock.Text += String.Format("   {0}: Bad Format", style) + "\n";
            }
         }
         outputBlock.Text += "\n";
      }
   }
}
// The example display the following output:
//    Attempting to convert ' 214 ':
//       None: Bad Format
//       AllowLeadingWhite, AllowTrailingWhite: 214
//       Integer, AllowTrailingSign: 214
//       AllowThousands, AllowCurrencySymbol: Bad Format
//       AllowDecimalPoint, AllowExponent: Bad Format
//    
//    Attempting to convert '1,064':
//       None: Bad Format
//       AllowLeadingWhite, AllowTrailingWhite: Bad Format
//       Integer, AllowTrailingSign: Bad Format
//       AllowThousands, AllowCurrencySymbol: 1064
//       AllowDecimalPoint, AllowExponent: Bad Format
//    
//    Attempting to convert '(0)':
//       None: Bad Format
//       AllowLeadingWhite, AllowTrailingWhite: Bad Format
//       Integer, AllowTrailingSign: Bad Format
//       AllowThousands, AllowCurrencySymbol: Bad Format
//       AllowDecimalPoint, AllowExponent: Bad Format
//    
//    Attempting to convert '1241+':
//       None: Bad Format
//       AllowLeadingWhite, AllowTrailingWhite: Bad Format
//       Integer, AllowTrailingSign: 1241
//       AllowThousands, AllowCurrencySymbol: Bad Format
//       AllowDecimalPoint, AllowExponent: Bad Format
//    
//    Attempting to convert ' + 214 ':
//       None: Bad Format
//       AllowLeadingWhite, AllowTrailingWhite: Bad Format
//       Integer, AllowTrailingSign: Bad Format
//       AllowThousands, AllowCurrencySymbol: Bad Format
//       AllowDecimalPoint, AllowExponent: Bad Format
//    
//    Attempting to convert ' +214 ':
//       None: Bad Format
//       AllowLeadingWhite, AllowTrailingWhite: Bad Format
//       Integer, AllowTrailingSign: 214
//       AllowThousands, AllowCurrencySymbol: Bad Format
//       AllowDecimalPoint, AllowExponent: Bad Format
//    
//    Attempting to convert '2153.0':
//       None: Bad Format
//       AllowLeadingWhite, AllowTrailingWhite: Bad Format
//       Integer, AllowTrailingSign: Bad Format
//       AllowThousands, AllowCurrencySymbol: Bad Format
//       AllowDecimalPoint, AllowExponent: 2153
//    
//    Attempting to convert '1e03':
//       None: Bad Format
//       AllowLeadingWhite, AllowTrailingWhite: Bad Format
//       Integer, AllowTrailingSign: Bad Format
//       AllowThousands, AllowCurrencySymbol: Bad Format
//       AllowDecimalPoint, AllowExponent: 1000
//    
//    Attempting to convert '1300.0e-2':
//       None: Bad Format
//       AllowLeadingWhite, AllowTrailingWhite: Bad Format
//       Integer, AllowTrailingSign: Bad Format
//       AllowThousands, AllowCurrencySymbol: Bad Format
//       AllowDecimalPoint, AllowExponent: 13



using System;
using System.Globalization;

public class Example
{
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      // Define a custom culture that uses "++" as a positive sign. 
      CultureInfo ci = new CultureInfo("");
      ci.NumberFormat.PositiveSign = "++";
      // Create an array of cultures.
      CultureInfo[] cultures = { ci, CultureInfo.InvariantCulture };
      // Create an array of strings to parse.
      string[] values = { "++1403", "-0", "+0", "+16034", 
                          Int16.MinValue.ToString(), "14.0", "18012" };
      // Parse the strings using each culture.
      foreach (CultureInfo culture in cultures)
      {
         outputBlock.Text += String.Format("Parsing with the '{0}' culture.", culture.Name) + "\n";
         foreach (string value in values)
         {
            try
            {
               ushort number = UInt16.Parse(value, culture);
               outputBlock.Text += String.Format("   Converted '{0}' to {1}.", value, number) + "\n";
            }
            catch (FormatException)
            {
               outputBlock.Text += String.Format("   The format of '{0}' is invalid.", value) + "\n";
            }
            catch (OverflowException)
            {
               outputBlock.Text += String.Format("   '{0}' is outside the range of a UInt16 value.", value) + "\n";
            }
         }
      }
   }
}
// The example displays the following output:
//       Parsing with the  culture.
//          Converted '++1403' to 1403.
//          Converted '-0' to 0.
//          The format of '+0' is invalid.
//          The format of '+16034' is invalid.
//          '-32768' is outside the range of a UInt16 value.
//          The format of '14.0' is invalid.
//          Converted '18012' to 18012.
//       Parsing with the '' culture.
//          The format of '++1403' is invalid.
//          Converted '-0' to 0.
//          Converted '+0' to 0.
//          Converted '+16034' to 16034.
//          '-32768' is outside the range of a UInt16 value.
//          The format of '14.0' is invalid.
//          Converted '18012' to 18012.


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.

Date

History

Reason

August 2009

Revised extensively.

Information enhancement.

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