Information
The topic you requested is included in another documentation set. For convenience, it's displayed below. Choose Switch to see the topic in its original location.

UTF32Encoding Class

Represents a UTF-32 encoding of Unicode characters.

System.Object
  System.Text.Encoding
    System.Text.UTF32Encoding

Namespace:  System.Text
Assemblies:   System.Text.Encoding.Extensions (in System.Text.Encoding.Extensions.dll)
  mscorlib (in mscorlib.dll)

public sealed class UTF32Encoding : Encoding

The UTF32Encoding type exposes the following members.

  NameDescription
Public methodUTF32Encoding()Initializes a new instance of the UTF32Encoding class.
Public methodUTF32Encoding(Boolean, Boolean)Initializes a new instance of the UTF32Encoding class. Parameters specify whether to use the big endian byte order and whether to provide a Unicode byte order mark.
Public methodUTF32Encoding(Boolean, Boolean, Boolean)Initializes a new instance of the UTF32Encoding class. Parameters specify whether to use the big endian byte order, whether to provide a Unicode byte order mark, and whether to throw an exception when an invalid encoding is detected.
Top

  NameDescription
Public propertyBodyNameWhen overridden in a derived class, gets a name for the current encoding that can be used with mail agent body tags. (Inherited from Encoding.)
Public propertyCodePageWhen overridden in a derived class, gets the code page identifier of the current Encoding. (Inherited from Encoding.)
Public propertyDecoderFallbackGets or sets the DecoderFallback object for the current Encoding object. (Inherited from Encoding.)
Public propertyEncoderFallbackGets or sets the EncoderFallback object for the current Encoding object. (Inherited from Encoding.)
Public propertyEncodingNameWhen overridden in a derived class, gets the human-readable description of the current encoding. (Inherited from Encoding.)
Public propertyHeaderNameWhen overridden in a derived class, gets a name for the current encoding that can be used with mail agent header tags. (Inherited from Encoding.)
Public propertyIsBrowserDisplayWhen overridden in a derived class, gets a value indicating whether the current encoding can be used by browser clients for displaying content. (Inherited from Encoding.)
Public propertyIsBrowserSaveWhen overridden in a derived class, gets a value indicating whether the current encoding can be used by browser clients for saving content. (Inherited from Encoding.)
Public propertyIsMailNewsDisplayWhen overridden in a derived class, gets a value indicating whether the current encoding can be used by mail and news clients for displaying content. (Inherited from Encoding.)
Public propertyIsMailNewsSaveWhen overridden in a derived class, gets a value indicating whether the current encoding can be used by mail and news clients for saving content. (Inherited from Encoding.)
Public propertyIsReadOnlyWhen overridden in a derived class, gets a value indicating whether the current encoding is read-only. (Inherited from Encoding.)
Public propertyIsSingleByteWhen overridden in a derived class, gets a value indicating whether the current encoding uses single-byte code points. (Inherited from Encoding.)
Public propertyWebNameWhen overridden in a derived class, gets the name registered with the Internet Assigned Numbers Authority (IANA) for the current encoding. (Inherited from Encoding.)
Public propertyWindowsCodePageWhen overridden in a derived class, gets the Windows operating system code page that most closely corresponds to the current encoding. (Inherited from Encoding.)
Top

  NameDescription
Public methodCloneWhen overridden in a derived class, creates a shallow copy of the current Encoding object. (Inherited from Encoding.)
Public methodEqualsDetermines whether the specified Object is equal to the current UTF32Encoding object. (Overrides Encoding.Equals(Object).)
Public methodGetByteCount(Char[])When overridden in a derived class, calculates the number of bytes produced by encoding all the characters in the specified character array. (Inherited from Encoding.)
Public methodGetByteCount(String)Calculates the number of bytes produced by encoding the characters in the specified String. (Overrides Encoding.GetByteCount(String).)
Public methodGetByteCount(Char*, Int32)Calculates the number of bytes produced by encoding a set of characters starting at the specified character pointer. (Overrides Encoding.GetByteCount(Char*, Int32).)
Public methodGetByteCount(Char[], Int32, Int32)Calculates the number of bytes produced by encoding a set of characters from the specified character array. (Overrides Encoding.GetByteCount(Char[], Int32, Int32).)
Public methodGetBytes(Char[])When overridden in a derived class, encodes all the characters in the specified character array into a sequence of bytes. (Inherited from Encoding.)
Public methodGetBytes(String)When overridden in a derived class, encodes all the characters in the specified string into a sequence of bytes. (Inherited from Encoding.)
Public methodGetBytes(Char[], Int32, Int32)When overridden in a derived class, encodes a set of characters from the specified character array into a sequence of bytes. (Inherited from Encoding.)
Public methodGetBytes(Char*, Int32, Byte*, Int32)Encodes a set of characters starting at the specified character pointer into a sequence of bytes that are stored starting at the specified byte pointer. (Overrides Encoding.GetBytes(Char*, Int32, Byte*, Int32).)
Public methodGetBytes(Char[], Int32, Int32, Byte[], Int32)Encodes a set of characters from the specified character array into the specified byte array. (Overrides Encoding.GetBytes(Char[], Int32, Int32, Byte[], Int32).)
Public methodGetBytes(String, Int32, Int32, Byte[], Int32)Encodes a set of characters from the specified String into the specified byte array. (Overrides Encoding.GetBytes(String, Int32, Int32, Byte[], Int32).)
Public methodGetCharCount(Byte[])When overridden in a derived class, calculates the number of characters produced by decoding all the bytes in the specified byte array. (Inherited from Encoding.)
Public methodGetCharCount(Byte*, Int32)Calculates the number of characters produced by decoding a sequence of bytes starting at the specified byte pointer. (Overrides Encoding.GetCharCount(Byte*, Int32).)
Public methodGetCharCount(Byte[], Int32, Int32)Calculates the number of characters produced by decoding a sequence of bytes from the specified byte array. (Overrides Encoding.GetCharCount(Byte[], Int32, Int32).)
Public methodGetChars(Byte[])When overridden in a derived class, decodes all the bytes in the specified byte array into a set of characters. (Inherited from Encoding.)
Public methodGetChars(Byte[], Int32, Int32)When overridden in a derived class, decodes a sequence of bytes from the specified byte array into a set of characters. (Inherited from Encoding.)
Public methodGetChars(Byte*, Int32, Char*, Int32)Decodes a sequence of bytes starting at the specified byte pointer into a set of characters that are stored starting at the specified character pointer. (Overrides Encoding.GetChars(Byte*, Int32, Char*, Int32).)
Public methodGetChars(Byte[], Int32, Int32, Char[], Int32)Decodes a sequence of bytes from the specified byte array into the specified character array. (Overrides Encoding.GetChars(Byte[], Int32, Int32, Char[], Int32).)
Public methodGetDecoderObtains a decoder that converts a UTF-32 encoded sequence of bytes into a sequence of Unicode characters. (Overrides Encoding.GetDecoder().)
Public methodGetEncoderObtains an encoder that converts a sequence of Unicode characters into a UTF-32 encoded sequence of bytes. (Overrides Encoding.GetEncoder().)
Public methodGetHashCodeReturns the hash code for the current instance. (Overrides Encoding.GetHashCode().)
Public methodGetMaxByteCountCalculates the maximum number of bytes produced by encoding the specified number of characters. (Overrides Encoding.GetMaxByteCount(Int32).)
Public methodGetMaxCharCountCalculates the maximum number of characters produced by decoding the specified number of bytes. (Overrides Encoding.GetMaxCharCount(Int32).)
Public methodGetPreambleReturns a Unicode byte order mark encoded in UTF-32 format, if the constructor for this instance requests a byte order mark. (Overrides Encoding.GetPreamble().)
Public methodGetString(Byte[])When overridden in a derived class, decodes all the bytes in the specified byte array into a string. (Inherited from Encoding.)
Public methodGetString(Byte*, Int32)When overridden in a derived class, decodes a specified number of bytes starting at a specified address into a string. (Inherited from Encoding.)
Public methodGetString(Byte[], Int32, Int32)Decodes a range of bytes from a byte array into a string. (Overrides Encoding.GetString(Byte[], Int32, Int32).)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodIsAlwaysNormalized()Gets a value indicating whether the current encoding is always normalized, using the default normalization form. (Inherited from Encoding.)
Public methodIsAlwaysNormalized(NormalizationForm)When overridden in a derived class, gets a value indicating whether the current encoding is always normalized, using the specified normalization form. (Inherited from Encoding.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
Top

Encoding is the process of transforming a set of Unicode characters into a sequence of bytes. Decoding is the process of transforming a sequence of encoded bytes into a set of Unicode characters.

The UTF-32 encoding represents each code point as a 32-bit integer. For more information about the UTFs and other encodings supported by System.Text, see Character Encoding in the .NET Framework.

The GetByteCount method determines how many bytes result in encoding a set of Unicode characters, and the GetBytes method performs the actual encoding.

Likewise, the GetCharCount method determines how many characters result in decoding a sequence of bytes, and the GetChars and GetString methods perform the actual decoding.

UTF32Encoding corresponds to the Windows code pages 12000 (little endian byte order) and 12001 (big endian byte order).

The encoder can use the big endian byte order (most significant byte first) or the little endian byte order (least significant byte first). For example, the Latin Capital Letter A (code point U+0041) is serialized as follows (in hexadecimal):

  • Big endian byte order: 00 00 00 41

  • Little endian byte order: 41 00 00 00

It is generally more efficient to store Unicode characters using the native byte order. For example, it is better to use the little endian byte order on little endian platforms, such as Intel computers.

The GetPreamble method retrieves an array of bytes that can include the byte order mark (BOM). If this byte array is prefixed to an encoded stream, it helps the decoder to identify the encoding format used.

For more information on byte order and the byte order mark, see The Unicode Standard at the Unicode home page.

NoteNote

To enable error detection and to make the class instance more secure, the application should use the UTF32Encoding constructor that takes a throwOnInvalidCharacters parameter, and set that parameter to true. With error detection, a method that detects an invalid sequence of characters or bytes throws a ArgumentException. Without error detection, no exception is thrown, and the invalid sequence is generally ignored.

The following code example demonstrates the behavior of UTF32Encoding, both with error detection enabled and without.

using System;
using System.Text;

public class SamplesUTF32Encoding  {

   public static void Main()  {

      // Create an instance of UTF32Encoding using little-endian byte order. 
      // This will be used for encoding.
      UTF32Encoding u32LE     = new UTF32Encoding( false, true );

      // Create two instances of UTF32Encoding using big-endian byte order: one with error detection and one without. 
      // These will be used for decoding.
      UTF32Encoding u32withED = new UTF32Encoding( true, true, true );
      UTF32Encoding u32noED   = new UTF32Encoding( true, true, false );

      // Create byte arrays from the same string containing the following characters: 
      //    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)
      String myStr = "za\u0306\u01FD\u03B2\uD8FF\uDCFF";

      // Encode the string using little-endian byte order. 
      byte[] myBytes = new byte[u32LE.GetByteCount( myStr )];
      u32LE.GetBytes( myStr, 0, myStr.Length, myBytes, 0 );

      // Decode the byte array with error detection.
      Console.WriteLine( "Decoding with error detection:" );
      PrintDecodedString( myBytes, u32withED );

      // Decode the byte array without error detection.
      Console.WriteLine( "Decoding without error detection:" );
      PrintDecodedString( myBytes, u32noED );

   }


   // Decode the bytes and display the string. 
   public static void PrintDecodedString( byte[] bytes, Encoding enc )  {

      try  {
         Console.WriteLine( "   Decoded string: {0}", enc.GetString( bytes, 0, bytes.Length ) );
      }
      catch ( System.ArgumentException e )  {
         Console.WriteLine( e.ToString() );
      }

      Console.WriteLine();

   }

}

.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

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Show:
© 2014 Microsoft