/// <summary> 
/// 给定文件的路径，读取文件的二进制数据，判断文件的编码类型 
/// </summary> 
/// <param name="FILE_NAME">文件路径</param> 
/// <returns>文件的编码类型</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> 
/// 通过给定的文件流，判断文件的编码类型 
/// </summary> 
/// <param name="fs">文件流</param> 
/// <returns>文件的编码类型</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 }; //带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> 
/// 判断是否是不带 BOM 的 UTF8 格式 
/// </summary> 
/// <param name="data"></param> 
/// <returns></returns> 
private static bool IsUTF8Bytes(byte[] data) 
{ 
    int charByteCounter = 1; 
    　 //计算当前正分析的字符应还有的字节数 
    byte curByte; //当前分析的字节. 
    for (int i = 0; i < data.Length; i++) 
    { 
        curByte = data[i]; 
        if (charByteCounter == 1) 
        { 
            if (curByte >= 0x80) 
            { 
                //判断当前 
                while (((curByte <<= 1) & 0x80) != 0) 
                { 
                    charByteCounter++; 
                } 
                //标记位首位若为非0 则至少以2个1开始 如:110XXXXX...........1111110X　 
                if (charByteCounter == 1 || charByteCounter > 6) 
                { 
                    return false; 
                } 
            } 
        } 
        else 
        { 
            //若是UTF-8 此时第一位必须为1 
            if ((curByte & 0xC0) != 0x80) 
            { 
                return false; 
            } 
            charByteCounter--; 
        } 
    } 
    if (charByteCounter > 1) 
    { 
        throw new Exception("非预期的byte格式"); 
    } 
    return true; 
} 

最后得到 的结果转换成：
string resault = GetType(@path);
Debug.Log(resault .BodyName.ToLower());