Decoder Class

Imports System.Text

Public Class Example
   Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
      ' These bytes in UTF-8 correspond to 3 different Unicode
      ' characters: space (U+0020), # (U+0023), and the biohazard
      ' symbol (U+2623).  Note the biohazard symbol requires 3 bytes
      ' in UTF-8 (hexadecimal e2, 98, a3).  Decoders store state across
      ' multiple calls to GetChars, handling the case when one char
      ' is in multiple byte arrays.
      Dim bytes1 As Byte() = {&H20, &H23, &HE2}
      Dim bytes2 As Byte() = {&H98, &HA3}

      Dim d As Decoder = Encoding.UTF8.GetDecoder()

      Dim arraySize As Integer = d.GetCharCount(bytes1, 0, bytes1.Length)
      arraySize += d.GetCharCount(bytes2, 0, bytes2.Length)

      Dim chars(arraySize - 1) As Char

      Dim charLen As Integer = d.GetChars(bytes1, 0, bytes1.Length, chars, 0)
      ' Use charLen to determine where new characters are written.
      charLen += d.GetChars(bytes2, 0, bytes2.Length, chars, charLen)

      Dim output As New String(chars, 0, charLen)
      outputBlock.Text += String.Format("'{0}'\n", output)
   End Sub
End Class

using System;
using System.Text;
public class Example
{
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      // These bytes in UTF-8 correspond to 3 different Unicode
      // characters: space (U+0020), # (U+0023), and the biohazard
      // symbol (U+2623).  Note the biohazard symbol requires 3 bytes
      // in UTF-8 (hexadecimal e2, 98, a3).  Decoders store state across
      // multiple calls to GetChars, handling the case when one char
      // is in multiple byte arrays.
      byte[] bytes1 = { 0x20, 0x23, 0xe2 };
      byte[] bytes2 = { 0x98, 0xa3 };

      Decoder d = Encoding.UTF8.GetDecoder();

      int arraySize = d.GetCharCount(bytes1, 0, bytes1.Length);
      arraySize += d.GetCharCount(bytes2, 0, bytes2.Length);  

      char[] chars = new char[arraySize];

      int charLen = d.GetChars(bytes1, 0, bytes1.Length, chars, 0);
      // Use charLen to determine where new characters are written.
      charLen += d.GetChars(bytes2, 0, bytes2.Length, chars, charLen);

      string output = new string(chars, 0, charLen);
      outputBlock.Text += String.Format("'{0}'\n", output);
   }
}