Read and Write 单一文件

private void operateFlatFile()
{
    string path;
    FileStream fs;
    byte[] _read, _write;
    int start, end;

    start = 0;
    end = 50;

    // read
    path = Server.MapPath("http://www.cnblogs.com/document/encode.txt");
    fs = new FileStream(path, FileMode.Open);
    _read = new byte[end];

    fs.Read(_read, start, end);
    fs.Close();

    // print
    Encoding ur = Encoding.GetEncoding("gb2312");
    string content = ur.GetString(_read);
    Response.Write(content + "<br>");

    // write
    path = Server.MapPath("http://www.cnblogs.com/document/new.txt");
    fs = new FileStream(path, FileMode.OpenOrCreate) ;

    Encoding uw = Encoding.GetEncoding("utf-8") ;
    _write = uw.GetBytes(content);

    fs.Write(_write, start, _write.Length);
    fs.Close();

    // show message

    Response.Write( "succ.");
}