C# 操作并口类,并口通信

c#已提供了串口通信组件SerialPort,但是C#并没有提供直接的并口通信组件,只好通过调用API来与并口通信

using System;
 using System.Runtime.InteropServices;
 namespace LptPrint_test
{
  /// <summary>
  /// LPTControl 的摘要说明。
  /// </summary>
   public class LPTControl
  {
    private string LptStr = "lpt1";
    public LPTControl(string l_LPT_Str)
    {
      //
      // TODO: 在此处添加构造函数逻辑
      //
      LptStr = l_LPT_Str;
    }
    [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);
    private int iHandle;
    public bool Open()
    {
      iHandle = CreateFile(LptStr, 0x40000000, 0, 0, 3, 0, 0);
      if (iHandle !=  - 1)
      {
        return true;
      }
      else
      {
        return false;
      }
    }
    public bool Write(String Mystring)
    {
      if (iHandle !=  - 1)
      {
        OVERLAPPED x = new OVERLAPPED();
        int i = 0;
        byte[] mybyte = System.Text.Encoding.Default.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!");
      }
    }
    public bool Write(byte[] mybyte)
    {
      if (iHandle !=  - 1)
      {
        OVERLAPPED x = new OVERLAPPED();
        int i = 0;
        WriteFile(iHandle, mybyte, mybyte.Length, ref i, ref x);
        return true;
      }
      else
      {
        throw new Exception("不能连接到打印机!");
      }
    }
    public bool Close()
    {
      return CloseHandle(iHandle);
    }
  }
}