UTF8 Property
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Encoding.UTF8 Property

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

Gets an encoding for the UTF-8 format.

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

public static Encoding UTF8 { get; }

Property Value

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

This property returns a UTF8Encoding object that encodes Unicode characters into a sequence of one to four bytes per character, and that decodes a UTF-8-encoded byte array to Unicode characters.

The UTF8Encoding object that is returned by this property may not have the appropriate behavior for your application. It uses replacement fallback to replace each string that it cannot encode and each byte that it cannot decode with a question mark ("?") character. Instead, you can call the UTF8Encoding.UTF8Encoding(Boolean, Boolean) constructor to instantiate a UTF8Encoding object whose fallback is either an EncoderFallbackException or a DecoderFallbackException, as the following example illustrates.


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


The following code example determines the number of bytes required to encode a character array, encodes the characters, and displays the resulting bytes.


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
*/


Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Windows Phone

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