pos机打印繁体中文字乱码的问题。。。。

[wu345654]

本人手头上的一个程序中需要打印一些繁体中文的文字。但是打印出来却是乱码，简体中文字正常显示。如果在机器上用记事本或者其他工具输入繁体字，打印到pos机上也不会出现问题，所以判断是程序还有不足的地方，如下是程序代码：

 class print_reg_paper
    {
        const int OPEN_EXISTING = 3;

        string prnPort = "LPT1";
        [DllImport("kernel32.dll", CharSet = CharSet.Auto)]
        private static extern IntPtr CreateFile(string lpFileName,
        int dwDesiredAccess,
        int dwShareMode,
        int lpSecurityAttributes,
        int dwCreationDisposition,
        int dwFlagsAndAttributes,
        int hTemplateFile);
        ArrayList al;

        public print_reg_paper(ArrayList als)
        {
            al = new ArrayList();
            this.al = als;
        }

        public string PrintLine(string str)
        {
            try
            {
                IntPtr iHandle = CreateFile(prnPort, 0x50000000, 0, 0, OPEN_EXISTING, 0, 0);
                if (iHandle.ToInt32() == -1)
                {
                    Console.WriteLine(iHandle.ToString());
                    return "没有连接打印机或者打印机端口不是LPT1";
                }
                else
                {
                    Console.WriteLine(iHandle.ToString());
                    FileStream fs = new FileStream(iHandle, FileAccess.ReadWrite);
                    StreamWriter sw = new StreamWriter(fs, System.Text.Encoding.GetEncoding("GB2312"));
                    Console.WriteLine(al[2].ToString());
                    sw.WriteLine(str);

                    sw.WriteLine();
                    
                    sw.WriteLine(al[1].ToString() + " " + al[2].ToString() + " " + al[3].ToString() + " " + al[4].ToString() + "件");
                    
                    sw.WriteLine();
                    sw.WriteLine(DateTime.Now);
                    sw.WriteLine(); sw.WriteLine(); sw.WriteLine(); sw.WriteLine();
                    sw.Close();
                    fs.Close();
                    return "打印机连接成功";
                }
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }
    }

[wu345654]

补充的是在

StreamWriter sw = new StreamWriter(fs, System.Text.Encoding.GetEncoding("GB2312"));
这句代码这里设置了很多种编码方式，比如“big” “utf-8” “gbk”等等一一测试都不行。求高手指点。。。。