class LptControl

    {

        private string LptStr = "lpt1";

        public LptControl(string l_LPT_Str)

        {

            LptStr = l_LPT_Str;

        }

        [StructLayout(LayoutKind.Sequential)]

        private struct OVERLAPPED

        {

            int Internal;

            int InternalHigh;

            int Offset;

            int OffSetHigh;

            int hEvent;

        }

        //调用DLL.

        [DllImport("kernel32.dll")]

        private static extern int CreateFile(string lpFileName, uint dwDesiredAccess, int dwShareMode, int lpSecurityAttributes, int dwCreationDisposition, int dwFlagsAndAttributes, int hTemplateFile);

        [DllImport("kernel32.dll")]

        private static extern bool WriteFile(int hFile, byte[] lpBuffer, int nNumberOfBytesToWrite, ref int lpNumberOfBytesWritten, ref OVERLAPPED lpOverlapped);

        [DllImport("kernel32.dll")]

        private static extern bool CloseHandle(int hObject);

        private int iHandle;

        /// <summary>

        /// 打开端口

        /// </summary>

        /// <returns></returns>

        public bool Open()

        {

            iHandle = CreateFile(LptStr, 0x40000000, , , , , );

            // iHandle = CreateFile(LptStr, GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0);

            if (iHandle != -)

            {

                return true;

            }

            else

            {

                return false;

            }

        }

        /// <summary>

        /// 打印字符串，通过调用该方法可以打印需要的字符串

        /// </summary>

        /// <param name="Mystring"></param>

        /// <returns></returns>

        public bool Write(String Mystring)

        {

             //如果端口为打开，则提示，打开，则打印

            if (iHandle != -)

            {

                OVERLAPPED x = new OVERLAPPED();

                int i = ;

                //byte[] mybyte = System.Text.Encoding.Default.GetBytes(Mystring);

                byte[] mybyte = Encoding.GetEncoding("GB2312").GetBytes(Mystring);

                bool b = WriteFile(iHandle, mybyte, mybyte.Length, ref i, ref x);

                return b;

            }

            else

            {

                throw new Exception("不能连接到打印机!");

            }

        }

        /// <summary>

        /// 打印命令，通过参数，可以打印小票打印机的一些命令，比如换行，行间距，打印位图等。

        /// </summary>

        /// <param name="mybyte"></param>

        /// <returns></returns>

        public bool Write(byte[] mybyte)

        {

            //如果端口为打开，则提示，打开，则打印

            if (iHandle != -)

            {

                OVERLAPPED x = new OVERLAPPED();

                int i = ;

                return WriteFile(iHandle, mybyte, mybyte.Length, ref i, ref x);

            }

            else

            {

                throw new Exception("不能连接到打印机!");

            }

        }

        /// <summary>

        /// 关闭端口

        /// </summary>

        /// <returns></returns>

        public bool Close()

        {

            return CloseHandle(iHandle);

        }

}

 /// <summary>

        /// 打印图片方法

        /// </summary>

        public void PrintOne()

        {

            //获取图片

            Bitmap bmp = new Bitmap(pictureBox1.Image);

            //设置字符行间距为n点行

            //byte[] data = new byte[] { 0x1B, 0x33, 0x00 };

            string send = "" + (char)() + (char)() + (char)();

            byte[] data = new byte[send.Length];

            for (int i = ; i < send.Length; i++)

            {

                data[i] = (byte)send[i];

            }

            lc.Write(data);

            data[] = (byte)'\x00';

            data[] = (byte)'\x00';

            data[] = (byte)'\x00';    // Clear to Zero.

            Color pixelColor;

            //ESC * m nL nH d1…dk   选择位图模式

            // ESC * m nL nH

            byte[] escBmp = new byte[] { 0x1B, 0x2A, 0x00, 0x00, 0x00 };

            escBmp[] = (byte)'\x21';

            //nL, nH

            escBmp[] = (byte)(bmp.Width % );

            escBmp[] = (byte)(bmp.Width / );

            //循环图片像素打印图片

            //循环高

            for (int i = ; i < (bmp.Height /  + ); i++)

            {

                //设置模式为位图模式

                lc.Write(escBmp);

                //循环宽

                for (int j = ; j < bmp.Width; j++)

                {

                    for (int k = ; k < ; k++)

                    {

                        if (((i * ) + k) < bmp.Height)  // if within the BMP size

                        {

                            pixelColor = bmp.GetPixel(j, (i * ) + k);

                            if (pixelColor.R == )

                            {

                                data[k / ] += (byte)( >> (k % ));

                            }

                        }

                    }

                    //一次写入一个data，24个像素

                    lc.Write(data);

                    data[] = (byte)'\x00';

                    data[] = (byte)'\x00';

                    data[] = (byte)'\x00';    // Clear to Zero.

                }

                //换行，打印第二行

                byte[] data2 = { 0xA };

                lc.Write(data2);

            } // data

            lc.Write("\n\n");

        }