<Type Name="Decoder" FullName="System.Text.Decoder" FullNameSP="System_Text_Decoder" Maintainer="ecma">
  <TypeSignature Language="ILASM" Value=".class public abstract serializable Decoder extends System.Object" />
  <TypeSignature Language="C#" Value="public abstract class Decoder" />
  <MemberOfLibrary>BCL</MemberOfLibrary>
  <AssemblyInfo>
    <AssemblyName>mscorlib</AssemblyName>
    <AssemblyPublicKey>[00 00 00 00 00 00 00 00 04 00 00 00 00 00 00 00 ]</AssemblyPublicKey>
    <AssemblyVersion>2.0.0.0</AssemblyVersion>
  </AssemblyInfo>
  <ThreadingSafetyStatement>All public static members of this type are safe for multithreaded operations. No instance members are guaranteed to be thread safe.</ThreadingSafetyStatement>
  <Base>
    <BaseTypeName>System.Object</BaseTypeName>
  </Base>
  <Interfaces />
  <Docs>
    <summary>
      <para> Converts blocks of bytes into blocks of characters,
      maintaining state across successive calls for reading from a <see cref="T:System.IO.Stream" />.
      </para>
    </summary>
    <remarks>
      <para>
        <block subset="none" type="note">Following instantiation of a decoder,
      sequential blocks of bytes are converted into blocks of characters through calls
      to the <see cref="M:System.Text.Decoder.GetChars(System.Byte[],System.Int32,System.Int32,System.Char[],System.Int32)" /> method. The decoder maintains state between the
      conversions, allowing it to correctly decode a character whose bytes span
      multiple blocks. This greatly assists decoding streams of bytes into
      characters. An instance of a specific implementation of the
   <see cref="T:System.Text.Decoder" />
   class is typically obtained through a call to the <see cref="M:System.Text.Encoding.GetDecoder" />
   method of a <see cref="T:System.Text.Encoding" /> object.</block>
      </para>
    </remarks>
    <example>
      <para> The following example demonstrates using the <see cref="T:System.Text.UTF8Encoding" />
implementation of the <see cref="T:System.Text.Decoder" /> class to convert two byte arrays to a character
array, where one character's bytes span multiple byte arrays. This demonstrates
how to use a <see cref="T:System.Text.Decoder" />
in streaming-like situations.</para>
      <code lang="C#">
using System;
using System.Text;

public class DecoderExample 
{
   public static void Main() 
   {
      // These bytes in UTF-8 correspond to 3 different
      // Unicode characters - A (U+0041), # (U+0023),
      // and the biohazard symbol (U+2623). Note the 
      // biohazard symbol requires 3 bytes in UTF-8 
      // (in hex, e2, 98, a3). Decoders store state across
      // multiple calls to GetChars, handling the case 
      // when one char spans multiple byte arrays.

      byte[] bytes1 = { 0x41, 0x23, 0xe2 };
      byte[] bytes2 = { 0x98, 0xa3 };
      char[] chars = new char[3]; 

      Decoder d = Encoding.UTF8.GetDecoder();
      int charLen = d.GetChars(bytes1, 0, bytes1.Length,
                               chars, 0);
      // charLen is 2.

      charLen += d.GetChars(bytes2, 0, bytes2.Length,
                            chars, charLen);
      // charLen is now 3. 

      foreach(char c in chars) 
         Console.Write("U+{0:x} ", (ushort)c);
   }
}
</code>
      <para>The output is </para>
      <c>
        <para>U+41 U+23 U+2623</para>
      </c>
    </example>
  </Docs>
  <Members>
    <Member MemberName=".ctor">
      <MemberSignature Language="ILASM" Value="family rtspecialname specialname instance void .ctor()" />
      <MemberSignature Language="C#" Value="protected Decoder ();" />
      <MemberType>Constructor</MemberType>
      <ReturnValue />
      <Parameters />
      <Docs>
        <summary>
          <para> Constructs a new instance of the <see cref="T:System.Text.Decoder" /> class.
   </para>
        </summary>
        <remarks>
          <para>This constructor is called only by classes that inherit from the <see cref="T:System.Text.Decoder" /> class.</para>
        </remarks>
      </Docs>
      <Excluded>0</Excluded>
    </Member>
    <Member MemberName="Convert">
      <MemberSignature Language="C#" Value="public virtual void Convert (byte* bytes, int byteCount, char* chars, int charCount, bool flush, out int bytesUsed, out int charsUsed, out bool completed);" />
      <MemberType>Method</MemberType>
      <ReturnValue>
        <ReturnType>System.Void</ReturnType>
      </ReturnValue>
      <Parameters>
        <Parameter Name="bytes" Type="System.Byte*" />
        <Parameter Name="byteCount" Type="System.Int32" />
        <Parameter Name="chars" Type="System.Char*" />
        <Parameter Name="charCount" Type="System.Int32" />
        <Parameter Name="flush" Type="System.Boolean" />
        <Parameter Name="bytesUsed" Type="System.Int32&amp;" RefType="out" />
        <Parameter Name="charsUsed" Type="System.Int32&amp;" RefType="out" />
        <Parameter Name="completed" Type="System.Boolean&amp;" RefType="out" />
      </Parameters>
      <Docs>
        <param name="bytes">To be added.</param>
        <param name="byteCount">To be added.</param>
        <param name="chars">To be added.</param>
        <param name="charCount">To be added.</param>
        <param name="flush">To be added.</param>
        <param name="bytesUsed">To be added.</param>
        <param name="charsUsed">To be added.</param>
        <param name="completed">To be added.</param>
        <summary>To be added.</summary>
        <remarks>To be added.</remarks>
        <since version=".NET 2.0" />
      </Docs>
    </Member>
    <Member MemberName="Convert">
      <MemberSignature Language="C#" Value="public virtual void Convert (byte[] bytes, int byteIndex, int byteCount, char[] chars, int charIndex, int charCount, bool flush, out int bytesUsed, out int charsUsed, out bool completed);" />
      <MemberType>Method</MemberType>
      <ReturnValue>
        <ReturnType>System.Void</ReturnType>
      </ReturnValue>
      <Parameters>
        <Parameter Name="bytes" Type="System.Byte[]" />
        <Parameter Name="byteIndex" Type="System.Int32" />
        <Parameter Name="byteCount" Type="System.Int32" />
        <Parameter Name="chars" Type="System.Char[]" />
        <Parameter Name="charIndex" Type="System.Int32" />
        <Parameter Name="charCount" Type="System.Int32" />
        <Parameter Name="flush" Type="System.Boolean" />
        <Parameter Name="bytesUsed" Type="System.Int32&amp;" RefType="out" />
        <Parameter Name="charsUsed" Type="System.Int32&amp;" RefType="out" />
        <Parameter Name="completed" Type="System.Boolean&amp;" RefType="out" />
      </Parameters>
      <Docs>
        <param name="bytes">To be added.</param>
        <param name="byteIndex">To be added.</param>
        <param name="byteCount">To be added.</param>
        <param name="chars">To be added.</param>
        <param name="charIndex">To be added.</param>
        <param name="charCount">To be added.</param>
        <param name="flush">To be added.</param>
        <param name="bytesUsed">To be added.</param>
        <param name="charsUsed">To be added.</param>
        <param name="completed">To be added.</param>
        <summary>To be added.</summary>
        <remarks>To be added.</remarks>
        <since version=".NET 2.0" />
      </Docs>
    </Member>
    <Member MemberName="Fallback">
      <MemberSignature Language="C#" Value="public System.Text.DecoderFallback Fallback { set; get; };" />
      <MemberType>Property</MemberType>
      <Attributes>
        <Attribute>
          <AttributeName>System.Runtime.InteropServices.ComVisible(false)</AttributeName>
        </Attribute>
      </Attributes>
      <ReturnValue>
        <ReturnType>System.Text.DecoderFallback</ReturnType>
      </ReturnValue>
      <Docs>
        <summary>To be added.</summary>
        <value>To be added.</value>
        <remarks>To be added.</remarks>
        <since version=".NET 2.0" />
      </Docs>
    </Member>
    <Member MemberName="FallbackBuffer">
      <MemberSignature Language="C#" Value="public System.Text.DecoderFallbackBuffer FallbackBuffer { get; };" />
      <MemberType>Property</MemberType>
      <Attributes>
        <Attribute>
          <AttributeName>System.Runtime.InteropServices.ComVisible(false)</AttributeName>
        </Attribute>
      </Attributes>
      <ReturnValue>
        <ReturnType>System.Text.DecoderFallbackBuffer</ReturnType>
      </ReturnValue>
      <Docs>
        <summary>To be added.</summary>
        <value>To be added.</value>
        <remarks>To be added.</remarks>
        <since version=".NET 2.0" />
      </Docs>
    </Member>
    <Member MemberName="GetCharCount">
      <MemberSignature Language="C#" Value="public virtual int GetCharCount (byte* bytes, int count, bool flush);" />
      <MemberType>Method</MemberType>
      <ReturnValue>
        <ReturnType>System.Int32</ReturnType>
      </ReturnValue>
      <Parameters>
        <Parameter Name="bytes" Type="System.Byte*" />
        <Parameter Name="count" Type="System.Int32" />
        <Parameter Name="flush" Type="System.Boolean" />
      </Parameters>
      <Docs>
        <param name="bytes">To be added.</param>
        <param name="count">To be added.</param>
        <param name="flush">To be added.</param>
        <summary>To be added.</summary>
        <returns>To be added.</returns>
        <remarks>To be added.</remarks>
        <since version=".NET 2.0" />
      </Docs>
    </Member>
    <Member MemberName="GetCharCount">
      <MemberSignature Language="ILASM" Value=".method public hidebysig virtual abstract int32 GetCharCount(class System.Byte[] bytes, int32 index, int32 count)" />
      <MemberSignature Language="C#" Value="public abstract int GetCharCount (byte[] bytes, int index, int count);" />
      <MemberType>Method</MemberType>
      <ReturnValue>
        <ReturnType>System.Int32</ReturnType>
      </ReturnValue>
      <Parameters>
        <Parameter Name="bytes" Type="System.Byte[]" />
        <Parameter Name="index" Type="System.Int32" />
        <Parameter Name="count" Type="System.Int32" />
      </Parameters>
      <Docs>
        <param name="bytes">A <see cref="T:System.Byte" /> array to decode. </param>
        <param name="index">A <see cref="T:System.Int32" /> that specifies the first index in <paramref name="bytes" /> to decode. </param>
        <param name="count">A <see cref="T:System.Int32" /> that specifies the number elements in <paramref name="bytes" /> to decode. </param>
        <summary>
          <para> Determines the exact number of characters that will be produced by
      decoding the specified range of the specified array of
      bytes.
      </para>
        </summary>
        <returns>
          <para> A <see cref="T:System.Int32" /> containing 
   the number of characters the next call to <see cref="M:System.Text.Decoder.GetChars(System.Byte[],System.Int32,System.Int32,System.Char[],System.Int32)" /> will produce if presented with the
   specified range of <paramref name="bytes" />
   .</para>
          <para>
            <block subset="none" type="note">This value takes into account the state in which the current instance was
   left following the last call to <see cref="M:System.Text.Decoder.GetChars(System.Byte[],System.Int32,System.Int32,System.Char[],System.Int32)" qualify="true" />. This
   contrasts with <see cref="M:System.Text.Encoding.GetChars(System.Byte[])" qualify="true" />, which does not maintain state information
   across subsequent calls.</block>
          </para>
        </returns>
        <remarks>
          <para>
            <block subset="none" type="behaviors">As described
      above.</block>
          </para>
          <para>
            <block subset="none" type="overrides">Override this
      method
      
      to return the appropriate value for a
      particular encoding.</block>
          </para>
          <para>
            <block subset="none" type="usage">Use this method to
      determine the appropriate size of a buffer to contain the
      decoded values.</block>
          </para>
        </remarks>
        <exception cref="T:System.ArgumentNullException">
          <paramref name="bytes" /> is <see langword="null" /> . </exception>
        <exception cref="T:System.ArgumentOutOfRangeException">
          <para>
            <paramref name="index" /> &lt; 0. </para>
          <para> -or- </para>
          <para>
            <paramref name="count" /> &lt; 0. </para>
          <para> -or- </para>
          <para>
            <paramref name="index " />and <paramref name="count " />do not specify a valid range in <paramref name="bytes" /> (i.e. (<paramref name="index" /> + <paramref name="count" />) &gt; <paramref name="bytes" />.Length).</para>
        </exception>
      </Docs>
      <Excluded>0</Excluded>
    </Member>
    <Member MemberName="GetCharCount">
      <MemberSignature Language="C#" Value="public virtual int GetCharCount (byte[] bytes, int index, int count, bool flush);" />
      <MemberType>Method</MemberType>
      <ReturnValue>
        <ReturnType>System.Int32</ReturnType>
      </ReturnValue>
      <Parameters>
        <Parameter Name="bytes" Type="System.Byte[]" />
        <Parameter Name="index" Type="System.Int32" />
        <Parameter Name="count" Type="System.Int32" />
        <Parameter Name="flush" Type="System.Boolean" />
      </Parameters>
      <Docs>
        <param name="bytes">To be added.</param>
        <param name="index">To be added.</param>
        <param name="count">To be added.</param>
        <param name="flush">To be added.</param>
        <summary>To be added.</summary>
        <returns>To be added.</returns>
        <remarks>To be added.</remarks>
        <since version=".NET 2.0" />
      </Docs>
    </Member>
    <Member MemberName="GetChars">
      <MemberSignature Language="C#" Value="public virtual int GetChars (byte* bytes, int byteCount, char* chars, int charCount, bool flush);" />
      <MemberType>Method</MemberType>
      <ReturnValue>
        <ReturnType>System.Int32</ReturnType>
      </ReturnValue>
      <Parameters>
        <Parameter Name="bytes" Type="System.Byte*" />
        <Parameter Name="byteCount" Type="System.Int32" />
        <Parameter Name="chars" Type="System.Char*" />
        <Parameter Name="charCount" Type="System.Int32" />
        <Parameter Name="flush" Type="System.Boolean" />
      </Parameters>
      <Docs>
        <param name="bytes">To be added.</param>
        <param name="byteCount">To be added.</param>
        <param name="chars">To be added.</param>
        <param name="charCount">To be added.</param>
        <param name="flush">To be added.</param>
        <summary>To be added.</summary>
        <returns>To be added.</returns>
        <remarks>To be added.</remarks>
        <since version=".NET 2.0" />
      </Docs>
    </Member>
    <Member MemberName="GetChars">
      <MemberSignature Language="ILASM" Value=".method public hidebysig virtual abstract int32 GetChars(class System.Byte[] bytes, int32 byteIndex, int32 byteCount, class System.Char[] chars, int32 charIndex)" />
      <MemberSignature Language="C#" Value="public abstract int GetChars (byte[] bytes, int byteIndex, int byteCount, char[] chars, int charIndex);" />
      <MemberType>Method</MemberType>
      <ReturnValue>
        <ReturnType>System.Int32</ReturnType>
      </ReturnValue>
      <Parameters>
        <Parameter Name="bytes" Type="System.Byte[]" />
        <Parameter Name="byteIndex" Type="System.Int32" />
        <Parameter Name="byteCount" Type="System.Int32" />
        <Parameter Name="chars" Type="System.Char[]" />
        <Parameter Name="charIndex" Type="System.Int32" />
      </Parameters>
      <Docs>
        <param name="bytes">A <see cref="T:System.Byte" /> array to decode. </param>
        <param name="byteIndex">A <see cref="T:System.Int32" /> that specifies the first index of <paramref name="bytes" /> from which to decode. </param>
        <param name="byteCount">A <see cref="T:System.Int32" /> that specifies the number elements in <paramref name="bytes" /> to decode. </param>
        <param name="chars">A <see cref="T:System.Char" /> array of characters to decode into. </param>
        <param name="charIndex">A <see cref="T:System.Int32" /> that specifies the first index of <paramref name="chars" /> to store the decoded bytes. </param>
        <summary>
          <para> Decodes the specified range of the specified array of bytes into the specified range
      of the specified array of characters for a particular encoding.
      </para>
        </summary>
        <returns>
          <para> A <see cref="T:System.Int32" /> containing
   the number of characters decoded into <paramref name="chars" /> for a
   particular encoding.
   </para>
        </returns>
        <remarks>
          <para>
            <block subset="none" type="note">
              <see cref="M:System.Text.Decoder.GetCharCount(System.Byte[],System.Int32,System.Int32)" /> can be used to determine the exact number of
   characters that will be produced for a specified range of bytes.
   Alternatively, <see cref="M:System.Text.Encoding.GetMaxCharCount(System.Int32)" /> of the <see cref="T:System.Text.Encoding" /> object that produced the current instance can be used to
   determine the maximum number of characters that might be produced for a specified
   number of bytes, regardless of the actual byte values.</block>
          </para>
          <para>
            <block subset="none" type="behaviors">As described above.</block>
          </para>
          <para>
            <block subset="none" type="overrides">Override this method to decode the values of a <see cref="T:System.Byte" /> array for a
particular encoding.</block>
          </para>
          <para>
            <block subset="none" type="usage">Use this method to
   decode the elements of a byte array for a particular encoding.</block>
          </para>
        </remarks>
        <exception cref="T:System.ArgumentException">
          <para>
            <paramref name="chars" /> does not contain sufficient space to store the decoded characters.</para>
        </exception>
        <exception cref="T:System.ArgumentNullException">
          <para>
            <paramref name="bytes " />is <see langword="null" /> . </para>
          <para>-or- </para>
          <para>
            <paramref name="chars " />is <see langword="null" /> . </para>
        </exception>
        <exception cref="T:System.ArgumentOutOfRangeException">
          <para>
            <paramref name="byteIndex" /> &lt; 0. </para>
          <para> -or- </para>
          <para>
            <paramref name="byteCount " /> &lt; 0. </para>
          <para> -or- </para>
          <para>
            <paramref name="charIndex " /> &lt; 0. </para>
          <para> -or- </para>
          <para>
            <paramref name="byteIndex" /> and <paramref name="byteCount" /> do not specify a valid range in <paramref name="bytes" /> (i.e. (<paramref name="byteIndex " />+ <paramref name="byteCount " /> ) &gt; <paramref name="bytes" />.Length). </para>
          <para>-or- </para>
          <para>
            <paramref name="charIndex" /> &gt; <paramref name="chars" />.Length.</para>
        </exception>
      </Docs>
      <Excluded>0</Excluded>
    </Member>
    <Member MemberName="GetChars">
      <MemberSignature Language="C#" Value="public virtual int GetChars (byte[] bytes, int byteIndex, int byteCount, char[] chars, int charIndex, bool flush);" />
      <MemberType>Method</MemberType>
      <ReturnValue>
        <ReturnType>System.Int32</ReturnType>
      </ReturnValue>
      <Parameters>
        <Parameter Name="bytes" Type="System.Byte[]" />
        <Parameter Name="byteIndex" Type="System.Int32" />
        <Parameter Name="byteCount" Type="System.Int32" />
        <Parameter Name="chars" Type="System.Char[]" />
        <Parameter Name="charIndex" Type="System.Int32" />
        <Parameter Name="flush" Type="System.Boolean" />
      </Parameters>
      <Docs>
        <param name="bytes">To be added.</param>
        <param name="byteIndex">To be added.</param>
        <param name="byteCount">To be added.</param>
        <param name="chars">To be added.</param>
        <param name="charIndex">To be added.</param>
        <param name="flush">To be added.</param>
        <summary>To be added.</summary>
        <returns>To be added.</returns>
        <remarks>To be added.</remarks>
        <since version=".NET 2.0" />
      </Docs>
    </Member>
    <Member MemberName="Reset">
      <MemberSignature Language="C#" Value="public virtual void Reset ();" />
      <MemberType>Method</MemberType>
      <ReturnValue>
        <ReturnType>System.Void</ReturnType>
      </ReturnValue>
      <Parameters />
      <Docs>
        <summary>To be added.</summary>
        <remarks>To be added.</remarks>
        <since version=".NET 2.0" />
      </Docs>
    </Member>
  </Members>
  <TypeExcluded>0</TypeExcluded>
  <Attributes>
    <Attribute>
      <AttributeName>System.Runtime.InteropServices.ComVisible(true)</AttributeName>
    </Attribute>
  </Attributes>
</Type>
