singrdk/base/Applications/Runtime/Full/System/Text/Decoder.cs

59 lines
2.7 KiB
C#

// ==++==
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
// ==--==
namespace System.Text
{
using System.Text;
using System;
// A Decoder is used to decode a sequence of blocks of bytes into a
// sequence of blocks of characters. Following instantiation of a decoder,
// sequential blocks of bytes are converted into blocks of characters through
// calls to the GetChars method. The decoder maintains state between the
// conversions, allowing it to correctly decode byte sequences that span
// adjacent blocks.
//
// Instances of specific implementations of the Decoder abstract base
// class are typically obtained through calls to the GetDecoder method
// of Encoding objects.
//
//| <include path='docs/doc[@for="Decoder"]/*' />
public abstract class Decoder
{
//| <include path='docs/doc[@for="Decoder.Decoder"]/*' />
protected Decoder() {
}
// Returns the number of characters the next call to GetChars will
// produce if presented with the given range of bytes. The returned value
// takes into account the state in which the decoder was left following the
// last call to GetChars. The state of the decoder is not affected
// by a call to this method.
//
//| <include path='docs/doc[@for="Decoder.GetCharCount"]/*' />
public abstract int GetCharCount(byte[] bytes, int index, int count);
// Decodes a range of bytes in a byte array into a range of characters
// in a character array. The method decodes byteCount bytes from
// bytes starting at index byteIndex, storing the resulting
// characters in chars starting at index charIndex. The
// decoding takes into account the state in which the decoder was left
// following the last call to this method.
//
// An exception occurs if the character array is not large enough to
// hold the complete decoding of the bytes. The GetCharCount method
// can be used to determine the exact number of characters that will be
// produced for a given range of bytes. Alternatively, the
// GetMaxCharCount method of the Encoding that produced this
// decoder can be used to determine the maximum number of characters that
// will be produced for a given number of bytes, regardless of the actual
// byte values.
//
//| <include path='docs/doc[@for="Decoder.GetChars"]/*' />
public abstract int GetChars(byte[] bytes, int byteIndex, int byteCount,
char[] chars, int charIndex);
}
}