/// <summary>/// 并口通信/// </summary>public interface IParallelContact : IPortContact{ActionResult Open(string port);}public class ParallelContact : IParallelContact{public bool Opened { get; set; }private string _port = string.Empty;public const short INVALID_HANDLE_VALUE = -1;public const uint GENERIC_READ = 0x80000000;public const uint GENERIC_WRITE = 0x40000000;public const int OPEN_EXISTING = 3;private int m_lpt = INVALID_HANDLE_VALUE;[StructLayout(LayoutKind.Sequential)]private struct OVERLAPPED{int Internal;int InternalHigh;int Offset;int OffSetHigh;int hEvent;}[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); //C#LPT端口打印类的操作 /// <summary>/// Closes this instance.关闭端口句柄/// </summary>public void Close(){if (m_lpt != INVALID_HANDLE_VALUE){CloseHandle(m_lpt);m_lpt = INVALID_HANDLE_VALUE;Opened = false;}}/// <summary>/// Writes the specified data.写入文本数据给打印机输出/// </summary>/// <param name="data">The data.</param>/// <returns></returns>public int Write(string data){if (Opened){byte[] byteData = System.Text.Encoding.Default.GetBytes(data);return this.Write(byteData);}return 0;}/// <summary>/// Writes the specified data.写入控制指令或文本给打印机输出/// </summary>/// <param name="data">The data.</param>/// <returns></returns>public int Write(byte[] data){int BytesWritten = 0;if (data.Length == 0) return BytesWritten;if (Opened){OVERLAPPED overlap = new OVERLAPPED();Thread.Sleep(40);if (WriteFile(m_lpt, data, data.Length, ref BytesWritten, ref overlap)){Thread.Sleep(40);}}return BytesWritten;}/// <summary>/// Opens the specified port.打开指定的并口/// </summary>/// <param name="port">The port.</param>/// <returns></returns>public ActionResult Open(string port){_port = port;m_lpt = CreateFile(port, GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0); //GENERIC_READ | GENERIC_WRITEif (m_lpt == INVALID_HANDLE_VALUE) return new ActionResult(false, "打开端口[" + port + "]失败！");Opened = true;return new ActionResult(true);}}