C# 判斷txt檔案編碼格式

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   /// <summary>     /// 擷取檔案的編碼格式     /// </summary>     public class EncodingType    {        /// <summary>         /// 給定檔案的路徑，讀取檔案的位元據，判斷檔案的編碼類別型         /// </summary>         /// <param name=“FILE_NAME“>檔案路徑</param>         /// <returns>檔案的編碼類別型</returns>         public static System.Text.Encoding GetType(string FILE_NAME)        {            FileStream fs = new FileStream(FILE_NAME, FileMode.Open, FileAccess.Read);            Encoding r = GetType(fs);            fs.Close();            return r;        }        /// <summary>         /// 通過給定的檔案流，判斷檔案的編碼類別型         /// </summary>         /// <param name=“fs“>檔案流</param>         /// <returns>檔案的編碼類別型</returns>         public static System.Text.Encoding GetType(FileStream fs)        {            byte[] Unicode = new byte[] { 0xFF, 0xFE, 0x41 };            byte[] UnicodeBIG = new byte[] { 0xFE, 0xFF, 0x00 };            byte[] UTF8 = new byte[] { 0xEF, 0xBB, 0xBF }; //帶BOM             Encoding reVal = Encoding.Default;            BinaryReader r = new BinaryReader(fs, System.Text.Encoding.Default);            int i;            int.TryParse(fs.Length.ToString(), out i);            byte[] ss = r.ReadBytes(i);            if (IsUTF8Bytes(ss) || (ss[0] == 0xEF && ss[1] == 0xBB && ss[2] == 0xBF))            {                reVal = Encoding.UTF8;            }            else if (ss[0] == 0xFE && ss[1] == 0xFF && ss[2] == 0x00)            {                reVal = Encoding.BigEndianUnicode;            }            else if (ss[0] == 0xFF && ss[1] == 0xFE && ss[2] == 0x41)            {                reVal = Encoding.Unicode;            }            r.Close();            return reVal;        }        /// <summary>         /// 判斷是否是不帶 BOM 的 UTF8 格式         /// </summary>         /// <param name=“data“></param>         /// <returns></returns>         private static bool IsUTF8Bytes(byte[] data)        {            int charByteCounter = 1; //計算當前正分析的字元應還有的位元組數             byte curByte; //當前分析的位元組.             for (int i = 0; i < data.Length; i++)            {                curByte = data[i];                if (charByteCounter == 1)                {                    if (curByte >= 0x80)                    {                        //判斷當前                         while (((curByte <<= 1) & 0x80) != 0)                        {                            charByteCounter++;                        }                        //標記位首位若為非0 則至少以2個1開始 如:110XXXXX...........1111110X                         if (charByteCounter == 1 || charByteCounter > 6)                        {                            return false;                        }                    }                }                else                {                    //若是UTF-8 此時第一位必須為1                     if ((curByte & 0xC0) != 0x80)                    {                        return false;                    }                    charByteCounter--;                }            }            if (charByteCounter > 1)            {                throw new Exception("非預期的byte格式");            }            return true;        }    } 

　　

C# 判斷txt檔案編碼格式