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IdnMapping.GetUnicode Method (String)

Decodes a string of one or more domain name labels, encoded according to the IDNA standard, to a string of Unicode characters.

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

public string GetUnicode(
	string ascii
)

Parameters

ascii
Type: System.String

The string to decode, which consists of one or more labels in the US-ASCII character range (U+0020 to U+007E) encoded according to the IDNA standard.

Return Value

Type: System.String
The Unicode equivalent of the IDNA substring specified by the ascii parameter.

ExceptionCondition
ArgumentNullException

ascii is null.

ArgumentException

ascii is invalid based on the AllowUnassigned and UseStd3AsciiRules properties, and the IDNA standard.

For more information about domain names, labels, and label separators, see the remarks for the IdnMapping.GetAscii(String, Int32, Int32) method.

The following example uses the GetAscii(String) method to convert an array of internationalized domain names to Punycode. The GetUnicode(String) method then converts the Punycode domain name back into the original domain name, but replaces the original label separators with the standard label separator.

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      string[] names = { "bücher.com", "мойдомен.рф", "παράδειγμα.δοκιμή",
                         "mycharity\u3002org",
                         "prose\u0000ware.com", "proseware..com", "a.org", 
                         "my_company.com" };
      IdnMapping idn = new IdnMapping();

      foreach (var name in names) {
         try {
            string punyCode = idn.GetAscii(name);
            string name2 = idn.GetUnicode(punyCode);
            Console.WriteLine("{0} --> {1} --> {2}", name, punyCode, name2); 
            Console.WriteLine("Original: {0}", ShowCodePoints(name));
            Console.WriteLine("Restored: {0}", ShowCodePoints(name2));
         }   
         catch (ArgumentException) { 
            Console.WriteLine("{0} is not a valid domain name.", name);
         }
         Console.WriteLine();
      }   
   }

   private static string ShowCodePoints(string str1) 
   {
      string output = "";
      foreach (var ch in str1)
         output += String.Format("U+{0} ", Convert.ToUInt16(ch).ToString("X4"));

      return output;
   }
}
// The example displays the following output: 
//    bücher.com --> xn--bcher-kva.com --> bücher.com 
//    Original: U+0062 U+00FC U+0063 U+0068 U+0065 U+0072 U+002E U+0063 U+006F U+006D 
//    Restored: U+0062 U+00FC U+0063 U+0068 U+0065 U+0072 U+002E U+0063 U+006F U+006D 
//     
//    мойдомен.рф --> xn--d1acklchcc.xn--p1ai --> мойдомен.рф 
//    Original: U+043C U+043E U+0439 U+0434 U+043E U+043C U+0435 U+043D U+002E U+0440 U+0444 
//    Restored: U+043C U+043E U+0439 U+0434 U+043E U+043C U+0435 U+043D U+002E U+0440 U+0444 
//     
//    παράδειγμα.δοκιμή --> xn--hxajbheg2az3al.xn--jxalpdlp --> παράδειγμα.δοκιμή 
//    Original: U+03C0 U+03B1 U+03C1 U+03AC U+03B4 U+03B5 U+03B9 U+03B3 U+03BC U+03B1 U+002E U+03B4 U+03BF U+03BA U+03B9 U+03BC U+03AE 
//    Restored: U+03C0 U+03B1 U+03C1 U+03AC U+03B4 U+03B5 U+03B9 U+03B3 U+03BC U+03B1 U+002E U+03B4 U+03BF U+03BA U+03B9 U+03BC U+03AE 
//     
//    mycharity。org --> mycharity.org --> mycharity.org 
//    Original: U+006D U+0079 U+0063 U+0068 U+0061 U+0072 U+0069 U+0074 U+0079 U+3002 U+006F U+0072 U+0067 
//    Restored: U+006D U+0079 U+0063 U+0068 U+0061 U+0072 U+0069 U+0074 U+0079 U+002E U+006F U+0072 U+0067 
//     
//    prose ware.com is not a valid domain name. 
//     
//    proseware..com is not a valid domain name. 
//     
//    a.org --> a.org --> a.org 
//    Original: U+0061 U+002E U+006F U+0072 U+0067 
//    Restored: U+0061 U+002E U+006F U+0072 U+0067 
//     
//    my_company.com --> my_company.com --> my_company.com 
//    Original: U+006D U+0079 U+005F U+0063 U+006F U+006D U+0070 U+0061 U+006E U+0079 U+002E U+0063 U+006F U+006D 
//    Restored: U+006D U+0079 U+005F U+0063 U+006F U+006D U+0070 U+0061 U+006E U+0079 U+002E U+0063 U+006F U+006D

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1
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