while( (len=stream.Read(buf,0,buf.Length)) != 0) {
        // 探测是否为Ascii编码
        if (isAscii)
            isAscii = det.isAscii(buf,len);

        // 如果不是Ascii编码，并且编码未确定，则继续探测
        if (!isAscii && !done)
                done = det.DoIt(buf,len, false);

    }
    stream.Close();
    stream.Dispose();
    //调用DatEnd方法，
    //如果引擎认为已经探测出了正确的编码，
//则会在此时调用ICharsetDetectionObserver的Notify方法
    det.DataEnd();

    if (isAscii) {
        Console.WriteLine("CHARSET = ASCII");
          found = true ;
    }
    else if (cdo.Charset != null)
    {
        Console.WriteLine("CHARSET = {0}",cdo.Charset);
        found = true;
    }
   
    if (!found) {
        string[] prob = det.getProbableCharsets() ;
        for(int i=0; i<prob.Length; i++) {
            Console.WriteLine("Probable Charset = " + prob[i]);
        }
    }
    Console.ReadLine();
http://www.cnblogs.com/hhh/archive/2007/01/27/632251.html