WinRT支持GB2312
在SL年代，有第三方类库支持 http://encoding4silverlight.codeplex.com
在RT版本有点不兼容，一直没时间看。今天闲的卵疼，就来一段代码兼容一下RT版本，迟点整合到我自己类库，直接上码。
/*
* ****************************************************
* Copyright (c) Aimeast. All rights reserved.
* ****************************************************
*/
using App2;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Windows.Storage;
using Windows.UI.Xaml;
namespace DBCSCodePage
{
public sealed class DBCSEncoding : Encoding
{
private const char LEAD_BYTE_CHAR = '\uFFFE';
private char[] _dbcsToUnicode = null;
private ushort[] _unicodeToDbcs = null;
private string _webName = null;
private static Dictionary<string, Tuple<char[], ushort[]>> _cache = null;
static DBCSEncoding()
{
if (!BitConverter.IsLittleEndian)
throw new PlatformNotSupportedException("Not supported big endian platform.");
_cache = new Dictionary<string, Tuple<char[], ushort[]>>();
}
private DBCSEncoding() { }
public async static Task<DBCSEncoding> GetDBCSEncoding(string name)
{
name = name.ToLower();
DBCSEncoding encoding = new DBCSEncoding();
encoding._webName = name;
if (_cache.ContainsKey(name))
{
var tuple = _cache[name];
encoding._dbcsToUnicode = tuple.Item1;
encoding._unicodeToDbcs = tuple.Item2;
return encoding;
}
var dbcsToUnicode = new char[0x10000];
var unicodeToDbcs = new ushort[0x10000];
/*
* According to many feedbacks, add this automatic function for finding resource in revision 1.0.0.1.
* We suggest that use the old method as below if you understand how to embed the resource.
* Please make sure the *.bin file was correctly embedded if throw an exception at here.
*/
//using (Stream stream = typeof(DBCSEncoding).Assembly.GetManifestResourceStream(typeof(DBCSEncoding).Namespace + "." + name + ".bin"))
//App.Current.
var file = await GetPackagedFileAsync();
using (Stream stream = await file.OpenStreamForReadAsync())
using (BinaryReader reader = new BinaryReader(stream))
{
for (int i = 0; i < 0xffff; i++)
{
ushort u = reader.ReadUInt16();
unicodeToDbcs[i] = u;
}
for (int i = 0; i < 0xffff; i++)
{
ushort u = reader.ReadUInt16();
dbcsToUnicode[i] = (char)u;
}
}
_cache[name] = new Tuple<char[], ushort[]>(dbcsToUnicode, unicodeToDbcs);
encoding._dbcsToUnicode = dbcsToUnicode;
encoding._unicodeToDbcs = unicodeToDbcs;
return encoding;
}
public override int GetByteCount(char[] chars, int index, int count)
{
int byteCount = 0;
ushort u;
char c;
for (int i = 0; i < count; index++, byteCount++, i++)
{
c = chars[index];
u = _unicodeToDbcs[c];
if (u > 0xff)
byteCount++;
}
return byteCount;
}
public override int GetBytes(char[] chars, int charIndex, int charCount, byte[] bytes, int byteIndex)
{
int byteCount = 0;
ushort u;
char c;
for (int i = 0; i < charCount; charIndex++, byteIndex++, byteCount++, i++)
{
c = chars[charIndex];
u = _unicodeToDbcs[c];
if (u == 0 && c != 0)
{
bytes[byteIndex] = 0x3f; // 0x3f == '?'
}
else if (u < 0x100)
{
bytes[byteIndex] = (byte)u;
}
else
{
bytes[byteIndex] = (byte)((u >> 8) & 0xff);
byteIndex++;
byteCount++;
bytes[byteIndex] = (byte)(u & 0xff);
}
}
return byteCount;
}
public override int GetCharCount(byte[] bytes, int index, int count)
{
return GetCharCount(bytes, index, count, null);
}
private int GetCharCount(byte[] bytes, int index, int count, DBCSDecoder decoder)
{
int charCount = 0;
ushort u;
char c;
for (int i = 0; i < count; index++, charCount++, i++)
{
u = 0;
if (decoder != null && decoder.pendingByte != 0)
{
u = decoder.pendingByte;
decoder.pendingByte = 0;
}
u = (ushort)(u << 8 | bytes[index]);
c = _dbcsToUnicode[u];
if (c == LEAD_BYTE_CHAR)
{
if (i < count - 1)
{
index++;
i++;
}
else if (decoder != null)
{
decoder.pendingByte = bytes[index];
return charCount;
}
}
}
return charCount;
}
public override int GetChars(byte[] bytes, int byteIndex, int byteCount, char[] chars, int charIndex)
{
return GetChars(bytes, byteIndex, byteCount, chars, charIndex, null);
}
private int GetChars(byte[] bytes, int byteIndex, int byteCount, char[] chars, int charIndex, DBCSDecoder decoder)
{
int charCount = 0;
ushort u;
char c;
for (int i = 0; i < byteCount; byteIndex++, charIndex++, charCount++, i++)
{
u = 0;
if (decoder != null && decoder.pendingByte != 0)
{
u = decoder.pendingByte;
decoder.pendingByte = 0;
}
u = (ushort)(u << 8 | bytes[byteIndex]);
c = _dbcsToUnicode[u];
if (c == LEAD_BYTE_CHAR)
{
if (i < byteCount - 1)
{
byteIndex++;
i++;
u = (ushort)(u << 8 | bytes[byteIndex]);
c = _dbcsToUnicode[u];
}
else if (decoder == null)
{
c = '\0';
}
else
{
decoder.pendingByte = bytes[byteIndex];
return charCount;
}
}
if (c == 0 && u != 0)
chars[charIndex] = '?';
else
chars[charIndex] = c;
}
return charCount;
}
public override int GetMaxByteCount(int charCount)
{
if (charCount < 0)
throw new ArgumentOutOfRangeException("charCount");
long count = charCount + 1;
count *= 2;
if (count > int.MaxValue)
throw new ArgumentOutOfRangeException("charCount");
return (int)count;
}
public override int GetMaxCharCount(int byteCount)
{
if (byteCount < 0)
throw new ArgumentOutOfRangeException("byteCount");
long count = byteCount + 3;
if (count > int.MaxValue)
throw new ArgumentOutOfRangeException("byteCount");
return (int)count;
}
public override Decoder GetDecoder()
{
return new DBCSDecoder(this);
}
public override string WebName
{
get
{
return _webName;
}
}
private sealed class DBCSDecoder : Decoder
{
private DBCSEncoding _encoding = null;
public DBCSDecoder(DBCSEncoding encoding)
{
_encoding = encoding;
}
public override int GetCharCount(byte[] bytes, int index, int count)
{
return _encoding.GetCharCount(bytes, index, count, this);
}
public override int GetChars(byte[] bytes, int byteIndex, int byteCount, char[] chars, int charIndex)
{
return _encoding.GetChars(bytes, byteIndex, byteCount, chars, charIndex, this);
}
public byte pendingByte;
}
public static async Task<StorageFile> GetPackagedFileAsync(string fileName = @"Maps\gb2312.bin")
{
StorageFolder installFolder = Windows.ApplicationModel.Package.Current.InstalledLocation;
return await installFolder.GetFileAsync(fileName);
}
}
}
这里需要用到一个包https://files.cnblogs.com/files/walleyekneel/Maps.zip
记得要设置content
调用方式
var encoding = await DBCSEncoding.GetDBCSEncoding("gb2312");
var str = encoding.GetBytes("122222");
性能问题不经测试，作者不承担此风险
