Big5-HKSCS編碼補遺

using System;

using System.Runtime.InteropServices;

using System.Text;

class HkscsHelper

{

    const uint HKSCS_ERR_INVALID_CHARS = 0x00000001;

    [DllImport("hkscs04.dll")]

    public static extern int HKSCS_Big5ToUnicode41(

        uint dwFlags, 

        [In][MarshalAs(UnmanagedType.LPStr)]string lpBig5Str, int cbBig5,

        [Out][MarshalAs(UnmanagedType.LPWStr)]StringBuilder lpUnicode41Str, 

        int cchUnicode41);

    [DllImport("hkscs04.dll")]

    public static extern int HKSCS_PUAToUnicode41(

        [In][MarshalAs(UnmanagedType.LPWStr)]string lpPUAStr, int cchPUA,

        [Out][MarshalAs(UnmanagedType.LPWStr)]StringBuilder lpUnicode41Str, 

        int cchUnicode41);

    public static string ConvertBig5(string srcString)

    {

        int srcLen = Encoding.GetEncoding(950).GetByteCount(srcString);

        int len = HKSCS_Big5ToUnicode41(HKSCS_ERR_INVALID_CHARS, 

                  srcString, srcLen, null, 0);

        StringBuilder sb = new StringBuilder(len);

        len = HKSCS_Big5ToUnicode41(HKSCS_ERR_INVALID_CHARS,

                  srcString, srcLen, sb, len);

        return sb.ToString().Substring(0, len);

    }

    public static string ConvertPua(string srcString)

    {

        int srcLen = srcString.Length;

        int len = HKSCS_PUAToUnicode41(srcString, srcLen, null, 0);

        var sb = new StringBuilder(len);

        len = HKSCS_PUAToUnicode41(srcString, srcLen, sb, len);

        return sb.ToString().Substring(0, len);

    }

}