Convert Big5 To Unicode for windows phone 7

參考:http://forums.create.msdn.com/forums/p/73736/553266.aspx

研究一下發現wp7的library中只提供了Unicode和Utf-8兩種編碼方式,
所以如果要使用網路上big5編碼的文字就要自己轉換了 不然會變亂碼

參考了MicroStrategy的文章之後
自己再重新包裝了一個工具類

需要先下載 這個編碼轉換的文字檔  導入專案中

之後把網路上抓回的Stream(big5)傳進去
就可以輸出想要的Sting(unicode)了~

public class Big5Util

{

    private static Dictionary<int, int> mBIG5_Unicode_MAP = new Dictionary<int, int> ();

    static Big5Util ()

    {

        StreamResourceInfo _ResourceInfo = Application.GetResourceStream (new Uri ("MyDemos;component/Resource/BIG5.TXT", UriKind.RelativeOrAbsolute));

        StreamReader _Reader = new StreamReader (_ResourceInfo.Stream);

        String line;

        while ((line = _Reader.ReadLine ()) != null)

        {

            if (line.StartsWith ("#"))

                continue; // Comments

            string[] lTokens = line.Split (new char[] { '\t' });

            if (lTokens.Length < 2)

                continue; // Not enough tokens

            try

            {

                mBIG5_Unicode_MAP.Add (int.Parse (lTokens[0].Substring (2), NumberStyles.HexNumber), int.Parse (lTokens[1].Substring (2), NumberStyles.HexNumber));

            }

            catch (Exception)

            {

                continue; // No mapping

            }

        }

    }

    public static string ToUni (Stream _str)

    {

        StringBuilder _StringBuilder = new StringBuilder ();

        byte[] big5Buffer = new byte[2];

        int input;

        while ((input = _str.ReadByte ()) != -1)

        {

            if (input > 0x81 && big5Buffer[0] == 0) //lead byte of big 5

            {

                big5Buffer[0] = (byte)input;

            }

            else if (big5Buffer[0] != 0)

            {

                big5Buffer[1] = (byte)input;

                int Big5Char = (big5Buffer[0] << 8) + big5Buffer[1];

                try

                {

                    int UTF8Char = mBIG5_Unicode_MAP[Big5Char];

                    _StringBuilder.Append ((char)UTF8Char);

                }

                catch (Exception)

                {

                    _StringBuilder.Append ((char)mBIG5_Unicode_MAP[0xA148]); // No mapping, use replacement character

                }

                big5Buffer = new byte[2];

            }

            else

            {

                _StringBuilder.Append ((char)input); // ASCII character

            }

        }

        return _StringBuilder.ToString ();

    }

}