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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)

'Declaration
Public Function GetUnicode ( _
	ascii As String _
) As String

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 Nothing.

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.

Imports System.Globalization

Module Example
   Public Sub Main()
      Dim names() As String = { "bücher.com", "мойдомен.рф", "παράδειγμα.δοκιμή",
                                "mycharity" + ChrW(&h3002) + "org",
                                "prose" + ChrW(0) + "ware.com", "proseware..com", "a.org", 
                                "my_company.com" }
      Dim idn As New IdnMapping()

      For Each name In names
         Try 
            Dim punyCode As String = idn.GetAscii(name)
            Dim name2 As String = idn.GetUnicode(punyCode)
            Console.WriteLine("{0} --> {1} --> {2}", name, punyCode, name2) 
            Console.WriteLine("Original: {0}", ShowCodePoints(name))
            Console.WriteLine("Restored: {0}", ShowCodePoints(name2))
         Catch e As ArgumentException 
            Console.WriteLine("{0} is not a valid domain name.", name)
         End Try
         Console.WriteLine()
      Next    
   End Sub 

   Private Function ShowCodePoints(str1 As String) As String 
      Dim output As String = "" 
      For Each ch In str1
         output += String.Format("U+{0} ", Convert.ToUInt16(ch).ToString("X4"))
      Next 
      Return output
   End Function 
End Module 
' 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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