IdnMapping.GetHashCode Method

Definition

Returns a hash code for this IdnMapping object.

public:
 override int GetHashCode();
public override int GetHashCode ();
override this.GetHashCode : unit -> int
Public Overrides Function GetHashCode () As Integer

Returns

One of four 32-bit signed constants derived from the properties of an IdnMapping object. The return value has no special meaning and is not suitable for use in a hash code algorithm.

Examples

The following example assumes that a single string can contain multiple email addresses separated by spaces. It removes the local part and the @ character from each email address, and passes the resulting domain name to the GetAscii(String, Int32) or GetAscii(String, Int32, Int32) method to create a Punycode domain name. The GetUnicode(String, Int32, Int32) method then converts the Punycode domain name back into the original domain name.

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      string email = "johann_doe@bücher.com john_doe@hotmail.com иван@мойдомен.рф";
      IdnMapping idn = new IdnMapping();
      int start = 0, end = 0;
      
      while (end >= 0) {
         start = email.IndexOf("@", end);
         end = email.IndexOf(" ", start);
         string domain = String.Empty;

         try {
            string punyCode = String.Empty;
            if (start >= 0 && end >= 0) { 
               domain = email.Substring(start + 1, end - start - 1);
               punyCode = idn.GetAscii(email, start + 1, end - start - 1);
            }
            else {
               domain = email.Substring(start + 1);
               punyCode = idn.GetAscii(email, start + 1);
            }
            string name2 = idn.GetUnicode(punyCode);
            Console.WriteLine("{0} --> {1} --> {2}", domain, punyCode, name2); 
         }   
         catch (ArgumentException) { 
            Console.WriteLine("{0} is not a valid domain name.", domain);
         }
         Console.WriteLine();
      }   
   }
}
// The example displays the following output:
//       bücher.com --> xn--bcher-kva.com --> bücher.com
//       
//       hotmail.com --> hotmail.com --> hotmail.com
//       
//       мойдомен.рф --> xn--d1acklchcc.xn--p1ai --> мойдомен.рф
Imports System.Globalization

Module Example
   Public Sub Main()
      Dim email As String = "johann_doe@bücher.com john_doe@hotmail.com иван@мойдомен.рф"
      Dim idn As New IdnMapping()
      Dim start, [end] As Integer
      
      Do While [end] >= 0
         start = email.IndexOf("@", [end])
         [end] = email.IndexOf(" ", start)
         Dim domain As String = String.Empty
         
         Try
            Dim punyCode As String = String.Empty
            If start >= 0 And [end] >= 0 Then 
               domain = email.Substring(start + 1, [end] - start - 1)
               punyCode = idn.GetAscii(email, start + 1, [end] - start - 1)
            Else
               domain = email.Substring(start + 1)
               punyCode = idn.GetAscii(email, start + 1)
            End If
            Dim name2 As String = idn.GetUnicode(punyCode)
            Console.WriteLine("{0} --> {1} --> {2}", domain, punyCode, name2) 
         Catch e As ArgumentException 
            Console.WriteLine("{0} is not a valid domain name.", domain)
         End Try
         Console.WriteLine()
      Loop   
   End Sub
End Module
' The example displays the following output:
'       bücher.com --> xn--bcher-kva.com --> bücher.com
'       
'       hotmail.com --> hotmail.com --> hotmail.com
'       
'       мойдомен.рф --> xn--d1acklchcc.xn--p1ai --> мойдомен.рф

Remarks

Override the GetHashCode method if your application needs to implement a meaningful hash code algorithm.

Applies to