System.Text.Decoder Class
Overview
The Decoder class converts a sequence of encoded bytes into a sequence of characters. It maintains state information between calls to handle byte sequences that span multiple blocks.
Namespace
System.Text
Assembly
System.Runtime.dll
Inheritance
Object → Decoder
Syntax
public abstract class DecoderMembers
Properties ▼
- DecoderFallback – Gets or sets an object that provides fallback data for a decoding operation.
- DecoderFallbackBuffer – Gets the fallback buffer associated with the current decoder.
Methods ▼
int GetCharCount(byte[] bytes, int index, int count)int GetCharCount(byte[] bytes, int index, int count, bool flush)int GetChars(byte[] bytes, int byteIndex, int byteCount, char[] chars, int charIndex)int GetChars(byte[] bytes, int byteIndex, int byteCount, char[] chars, int charIndex, bool flush)void Reset()
Examples
// Decode a UTF‑8 byte array using a Decoder instance.
byte[] utf8Bytes = new byte[] { 0x48, 0x65, 0x6C, 0x6C, 0x6F, 0x20, 0xE2, 0x98, 0x83 };
Decoder decoder = Encoding.UTF8.GetDecoder();
int charCount = decoder.GetCharCount(utf8Bytes, 0, utf8Bytes.Length);
char[] chars = new char[charCount];
decoder.GetChars(utf8Bytes, 0, utf8Bytes.Length, chars, 0);
string result = new string(chars);
Console.WriteLine(result); // Output: Hello ☃
Remarks
When decoding streams of bytes that may not be aligned on character boundaries, use a Decoder to preserve state between calls. This ensures that incomplete byte sequences are correctly handled.