Encoding.UTF8 Property

Property Value

Type: System.Text.Encoding
An encoding for the UTF-8 format.

Imports System.Text

Module Example
   Public Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
      Dim enc As Encoding = New UTF8Encoding(True, True)
      Dim value As String = String.Format("{0} {1}{2} {3}", 
                            ChrW(&h00C4), ChrW(&hD802), ChrW(&h0033), ChrW(&h00AE))

      Try
         Dim bytes() As Byte = enc.GetBytes(value)
         For Each byt As Byte In bytes
            outputBlock.Text &= String.Format("{0:X2} ", byt)
         Next
         outputBlock.Text &= vbCrLf
         Dim value2 As String = enc.GetString(bytes, 0, bytes.Length)
         outputBlock.Text &= value2 & vbCrLf
      Catch e As EncoderFallbackException
         outputBlock.Text += String.Format("Unable to encode {0} at index {1}",  
                           If(e.IsUnknownSurrogate(), 
                              String.Format("U+{0:X4} U+{1:X4}", 
                                            Convert.ToUInt16(e.CharUnknownHigh),
                                            Convert.ToUInt16(e.CharUnknownLow)),
                              String.Format("U+{0:X4}", 
                                            Convert.ToUInt16(e.CharUnknown))),
                           e.Index) & vbCrLf
      End Try
   End Sub
End Module
' The example displays the following output:
'       Unable to encode U+D802 at index 2

using System;
using System.Text;

public class Example
{
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      Encoding enc = new UTF8Encoding(true, true);
      string value = "\u00C4 \uD802\u0033 \u00AE";

      try
      {
         byte[] bytes = enc.GetBytes(value);
         foreach (var byt in bytes)
            outputBlock.Text += String.Format("{0:X2} ", byt);
         outputBlock.Text += "\n";

         string value2 = enc.GetString(bytes, 0, bytes.Length);
         outputBlock.Text += value2 + "\n";
      }
      catch (EncoderFallbackException e)
      {
         outputBlock.Text += String.Format("Unable to encode {0} at index {1}",
                           e.IsUnknownSurrogate() ?
                              String.Format("U+{0:X4} U+{1:X4}",
                                            Convert.ToUInt16(e.CharUnknownHigh),
                                            Convert.ToUInt16(e.CharUnknownLow)) :
                              String.Format("U+{0:X4}",
                                            Convert.ToUInt16(e.CharUnknown)),
                           e.Index) + "\n";
      }
   }
}
// The example displays the following output:
//        Unable to encode U+D802 at index 2

Imports System.Text

Public Class Example

   Private Shared outputBlock As System.Windows.Controls.TextBlock

   Public Shared Sub Demo(ByVal outBlock As System.Windows.Controls.TextBlock)

      outputBlock = outBlock   

      ' The characters to encode:
      '    Latin Small Letter Z (U+007A)
      '    Latin Small Letter A (U+0061)
      '    Combining Breve (U+0306)
      '    Latin Small Letter AE With Acute (U+01FD)
      '    Greek Small Letter Beta (U+03B2)
      '    a high-surrogate value (U+D8FF)
      '    a low-surrogate value (U+DCFF)
      Dim myChars() As Char = {"z"c, "a"c, ChrW(&H306), ChrW(&H1FD), ChrW(&H3B2), ChrW(&HD8FF), ChrW(&HDCFF)}

      ' Get different encodings.
      Dim u8 As Encoding = Encoding.UTF8
      Dim u16LE As Encoding = Encoding.Unicode
      Dim u16BE As Encoding = Encoding.BigEndianUnicode

      ' Encode the entire array, and print out the counts and the resulting bytes.
      PrintCountsAndBytes(myChars, u8)
      PrintCountsAndBytes(myChars, u16LE)
      PrintCountsAndBytes(myChars, u16BE)
   End Sub 

   Public Shared Sub PrintCountsAndBytes(ByVal chars() As Char, ByVal enc As Encoding)
      ' Display the name of the encoding used.
      outputBlock.Text += String.Format("{0,-30} :", enc.ToString())

      ' Display the exact byte count.
      Dim iBC As Integer = enc.GetByteCount(chars)
      outputBlock.Text += String.Format(" {0,-3}", iBC)

      ' Display the maximum byte count.
      Dim iMBC As Integer = enc.GetMaxByteCount(chars.Length)
      outputBlock.Text += String.Format(" {0,-3} :", iMBC)

      ' Encode the array of chars.
      Dim bytes As Byte() = enc.GetBytes(chars)

      ' Display all the encoded bytes.
      PrintHexBytes(bytes)
   End Sub 

   Public Shared Sub PrintHexBytes(ByVal bytes() As Byte)
      If bytes Is Nothing OrElse bytes.Length = 0 Then
         outputBlock.Text &= "<none>" & vbCrLf
      Else
         Dim i As Integer
         For i = 0 To bytes.Length - 1
            outputBlock.Text += String.Format("{0:X2} ", bytes(i))
         Next i
         outputBlock.Text &= vbCrLf
      End If
   End Sub 
End Class 
' This example produces the following output.
'    System.Text.UTF8Encoding       : 12  24  :7A 61 CC 86 C7 BD CE B2 F1 8F B3 BF
'    System.Text.UnicodeEncoding    : 14  16  :7A 00 61 00 06 03 FD 01 B2 03 FF D8 FF DC
'    System.Text.UnicodeEncoding    : 14  16  :00 7A 00 61 03 06 01 FD 03 B2 D8 FF DC FF

using System;
using System.Text;

public class Example
{
   private static System.Windows.Controls.TextBlock outputBlock;

   public static void Demo(System.Windows.Controls.TextBlock outBlock)
   {
      outputBlock = outBlock;

      // The characters to encode:
      //    Latin Small Letter Z (U+007A)
      //    Latin Small Letter A (U+0061)
      //    Combining Breve (U+0306)
      //    Latin Small Letter AE With Acute (U+01FD)
      //    Greek Small Letter Beta (U+03B2)
      //    a high-surrogate value (U+D8FF)
      //    a low-surrogate value (U+DCFF)
      char[] myChars = new char[] { 'z', 'a', '\u0306', '\u01FD', '\u03B2', '\uD8FF', '\uDCFF' };

      // Get different encodings.
      Encoding u8 = Encoding.UTF8;
      Encoding u16LE = Encoding.Unicode;
      Encoding u16BE = Encoding.BigEndianUnicode;

      // Encode the entire array, and print out the counts and the resulting bytes.
      PrintCountsAndBytes(myChars, u8);
      PrintCountsAndBytes(myChars, u16LE);
      PrintCountsAndBytes(myChars, u16BE);
   }

   public static void PrintCountsAndBytes(char[] chars, Encoding enc)
   {
      // Display the name of the encoding used.
      outputBlock.Text += String.Format("{0,-30} :", enc.ToString());

      // Display the exact byte count.
      int iBC = enc.GetByteCount(chars);
      outputBlock.Text += String.Format(" {0,-3}", iBC);

      // Display the maximum byte count.
      int iMBC = enc.GetMaxByteCount(chars.Length);
      outputBlock.Text += String.Format(" {0,-3} :", iMBC);

      // Encode the array of chars.
      byte[] bytes = enc.GetBytes(chars);

      // Display all the encoded bytes.
      PrintHexBytes(bytes);
   }

   public static void PrintHexBytes(byte[] bytes)
   {
      if ((bytes == null) || (bytes.Length == 0))
         outputBlock.Text += "<none>" + "\n";
      else
      {
         for (int i = 0; i < bytes.Length; i++)
            outputBlock.Text += String.Format("{0:X2} ", bytes[i]);
         outputBlock.Text += "\n";
      }
   }
}
/* 
This code produces the following output.
   System.Text.UTF8Encoding       : 12  24  :7A 61 CC 86 C7 BD CE B2 F1 8F B3 BF
   System.Text.UnicodeEncoding    : 14  16  :7A 00 61 00 06 03 FD 01 B2 03 FF D8 FF DC
   System.Text.UnicodeEncoding    : 14  16  :00 7A 00 61 03 06 01 FD 03 B2 D8 FF DC FF
*/