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Categories / C# / File Stream

 

Guess Text File Encoding

//---------------------------------------------------------------------------------------- // Copyright (C) 2008  ???? ????? // // ?????       // ? ? ??      TxtFileEncoding.cs // ???????   ???????????????(Encoding) // // ?????      ???    2008-3-22 13:01:03 // // ????? // ????? //  // ????? // ????? //---------------------------------------------------------------------------------------- using System; using System.Text; using System.IO; namespace MaoCaiJun.DataBase.Sys.Common {     /// <summary>     /// ???????????????(Encoding)?     /// </summary>      class TxtFileEncoding     {         //public TxtFileEncoding()         //{         //    //         //    // TODO: ???????????         //    //         //}         /// <summary>         /// ????????????????????????????????Encoding.Default?????         /// </summary>         /// <param name="fileName">????</param>         /// <returns></returns>         public static Encoding GetEncoding(string fileName)         {             return GetEncoding(fileName, Encoding.Default);         }         /// <summary>         /// ???????????????         /// </summary>         /// <param name="stream">??????</param>         /// <returns></returns>         public static Encoding GetEncoding(FileStream stream)         {             return GetEncoding(stream, Encoding.Default);         }         /// <summary>         /// ??????????????         /// </summary>         /// <param name="fileName">????</param>         /// <param name="defaultEncoding">??????????????????????????????????????</param>         /// <returns></returns>         public static Encoding GetEncoding(string fileName, Encoding defaultEncoding)         {             FileStream fs = new FileStream(fileName, FileMode.Open);             Encoding targetEncoding = GetEncoding(fs, defaultEncoding);             fs.Close();             return targetEncoding;         }         /// <summary>         /// ???????????????         /// </summary>         /// <param name="stream">??????</param>         /// <param name="defaultEncoding">??????????????????????????????????????</param>         /// <returns></returns>         public static Encoding GetEncoding(FileStream stream, Encoding defaultEncoding)         {             Encoding targetEncoding = defaultEncoding;             if (stream != null && stream.Length >= 2)             {                 //???????4???                 byte byte1 = 0;                 byte byte2 = 0;                 byte byte3 = 0;                 byte byte4 = 0;                 //????Seek??                 long origPos = stream.Seek(0, SeekOrigin.Begin);                 stream.Seek(0, SeekOrigin.Begin);                 int nByte = stream.ReadByte();                 byte1 = Convert.ToByte(nByte);                 byte2 = Convert.ToByte(stream.ReadByte());                 if (stream.Length >= 3)                 {                     byte3 = Convert.ToByte(stream.ReadByte());                 }                 if (stream.Length >= 4)                 {                     byte4 = Convert.ToByte(stream.ReadByte());                 }                 //???????4?????Encoding                 //Unicode {0xFF, 0xFE};                 //BE-Unicode {0xFE, 0xFF};                 //UTF8 = {0xEF, 0xBB, 0xBF};                 if (byte1 == 0xFE && byte2 == 0xFF)//UnicodeBe                 {                     targetEncoding = Encoding.BigEndianUnicode;                 }                 if (byte1 == 0xFF && byte2 == 0xFE && byte3 != 0xFF)//Unicode                 {                     targetEncoding = Encoding.Unicode;                 }                 if (byte1 == 0xEF && byte2 == 0xBB && byte3 == 0xBF)//UTF8                 {                     targetEncoding = Encoding.UTF8;                 }                 //??Seek??                        stream.Seek(origPos, SeekOrigin.Begin);             }             return targetEncoding;         }     } }