String.Format Method (IFormatProvider, String, array<Object[])

Parameters

• provider
  Type: System.IFormatProvider
  An object that supplies culture-specific formatting information.

• format
  Type: System.String
  A composite format string (see Remarks).

• args
  Type: array<System.Object[]
  An object array that contains zero or more objects to format.

Return Value

Type: System.String
A copy of format in which the format items have been replaced by the string representation of the corresponding objects in args.

Imports System.Globalization
Imports System.Windows.Media

Module Example
   Public Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
      outputBlock.FontFamily = New FontFamily("Courier New")

      Dim cultureNames() As String = {"en-US", "fr-FR", "de-DE", "es-ES"}

      Dim dateToDisplay As Date = #9/1/2009 6:32:00 PM#
      Dim value As Double = 9164.32

      outputBlock.Text &= "Culture     Date                                Value" & vbCrLf
      outputBlock.Text &= vbCrLf
      For Each cultureName As String In cultureNames
         Dim culture As New CultureInfo(cultureName)
         Dim output As String = String.Format(culture, "{0,-11} {1,-35:D} {2:N}", _
                                              culture.Name, dateToDisplay, value)
         outputBlock.Text &= output & vbCrLf
      Next
   End Sub
End Module
' The example displays the following output:
'       Culture     Date                                Value
'       
'       en-US       Tuesday, September 01, 2009         9,164.32
'       fr-FR       mardi 1 septembre 2009              9 164,32
'       de-DE       Dienstag, 1. September 2009         9.164,32
'       es-ES       martes, 01 de septiembre de 2009    9.164,32

using System;
using System.Globalization;
using System.Windows.Media;

public class Example
{
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      outputBlock.FontFamily = new FontFamily("Courier New");

      string[] cultureNames = { "en-US", "fr-FR", "de-DE", "es-ES" };

      DateTime dateToDisplay = new DateTime(2009, 9, 1, 18, 32, 0);
      double value = 9164.32;

      outputBlock.Text += "Culture     Date                                Value\n" + "\n";
      foreach (string cultureName in cultureNames)
      {
         CultureInfo culture = new CultureInfo(cultureName);
         string output = String.Format(culture, "{0,-11} {1,-35:D} {2:N}",
                                       culture.Name, dateToDisplay, value);
         outputBlock.Text += output + "\n";
      }
   }
}
// The example displays the following output:
//    Culture     Date                                Value
//    
//    en-US       Tuesday, September 01, 2009         9,164.32
//    fr-FR       mardi 1 septembre 2009              9 164,32
//    de-DE       Dienstag, 1. September 2009         9.164,32
//    es-ES       martes, 01 de septiembre de 2009    9.164,32

Module Example
   Public Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
      Dim acctNumber As Integer = 79203159
      outputBlock.Text += String.Format(New CustomerFormatter, "{0}", acctNumber) & vbCrLf
      outputBlock.Text += String.Format(New CustomerFormatter, "{0:G}", acctNumber) & vbCrLf
      outputBlock.Text += String.Format(New CustomerFormatter, "{0:S}", acctNumber) & vbCrLf
      outputBlock.Text += String.Format(New CustomerFormatter, "{0:P}", acctNumber) & vbCrLf
      Try
         outputBlock.Text += String.Format(New CustomerFormatter, "{0:X}", acctNumber) & vbCrLf
      Catch e As FormatException
         outputBlock.Text += e.Message + vbCrLf
      End Try   
   End Sub
End Module

Public Class CustomerFormatter : Implements IFormatProvider, ICustomFormatter
   Public Function GetFormat(ByVal type As Type) As Object _
                   Implements IFormatProvider.GetFormat
      If type Is GetType(ICustomFormatter) Then
         Return Me
      Else
         Return Nothing
      End If
   End Function

   Public Function Format(ByVal fmt As String, _
                        ByVal arg As Object, _
                        ByVal formatProvider As IFormatProvider) As String _
                 Implements ICustomFormatter.Format
      If Not Me.Equals(formatProvider) Then
         Return Nothing
      Else
         If String.IsNullOrEmpty(fmt) Then fmt = "G"

         Dim customerString As String = arg.ToString()
         If customerString.Length < 8 Then _
            customerString = customerString.PadLeft(8, "0"c)

         Select Case fmt
            Case "G"
               Return customerString.Substring(0, 1) & "-" & _
                                customerString.Substring(1, 5) & "-" & _
                                customerString.Substring(6)
            Case "S"
               Return customerString.Substring(0, 1) & "/" & _
                                customerString.Substring(1, 5) & "/" & _
                                customerString.Substring(6)
            Case "P"
               Return customerString.Substring(0, 1) & "." & _
                                customerString.Substring(1, 5) & "." & _
                                customerString.Substring(6)
            Case Else
               Throw New FormatException( _
                         String.Format("The '{0}' format specifier is not supported.", fmt))
         End Select
      End If
   End Function
End Class
' The example displays the following output:
'       7-92031-59
'       7-92031-59
'       7/92031/59
'       7.92031.59
'       The 'X' format specifier is not supported.

using System;

public class Example
{
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      int acctNumber = 79203159;
      outputBlock.Text += String.Format(new CustomerFormatter(), "{0}", acctNumber) + "\n";
      outputBlock.Text += String.Format(new CustomerFormatter(), "{0:G}", acctNumber) + "\n";
      outputBlock.Text += String.Format(new CustomerFormatter(), "{0:S}", acctNumber) + "\n";
      outputBlock.Text += String.Format(new CustomerFormatter(), "{0:P}", acctNumber) + "\n";
      try {
         outputBlock.Text += String.Format(new CustomerFormatter(), "{0:X}", acctNumber) + "\n";
      }
      catch (FormatException e) {
         outputBlock.Text += e.Message + "\n";
      }
   }
}

public class CustomerFormatter : IFormatProvider, ICustomFormatter
{
   public object GetFormat(Type formatType)
   {
      if (formatType == typeof(ICustomFormatter))
         return this;
      else
         return null;
   }

   public string Format(string format,
                          object arg,
                          IFormatProvider formatProvider)
   {
      if (!this.Equals(formatProvider))
      {
         return null;
      }
      else
      {
         if (String.IsNullOrEmpty(format))
            format = "G";

         string customerString = arg.ToString();
         if (customerString.Length < 8)
            customerString = customerString.PadLeft(8, '0');

         format = format.ToUpper();
         switch (format)
         {   
            case "G":
               return customerString.Substring(0, 1) + "-" +
                                customerString.Substring(1, 5) + "-" +
                                customerString.Substring(6);
            case "S":
               return customerString.Substring(0, 1) + "/" +
                                customerString.Substring(1, 5) + "/" +
                                customerString.Substring(6);
            case "P":            
               return customerString.Substring(0, 1) + "." +
                                customerString.Substring(1, 5) + "." +
                                customerString.Substring(6);
            default:
               throw new FormatException(
                         String.Format("The '{0}' format specifier is not supported.", format));                                
         }
      }
   }
}
// The example displays the following output:
//       7-92031-59
//       7-92031-59
//       7/92031/59
//       7.92031.59
//       The 'X' format specifier is not supported.