C#编程实现向并口设备发送指令、获取并口设备的状态

 using System; using System.Diagnostics; using System.Runtime.InteropServices; using System.Text; using System.Windows.Forms; namespace ParallelPort { public partial class Form1 : Form { const uint GENERIC_READ = 0x80000000; const uint GENERIC_WRITE = 0x40000000; const uint FILE_ATTRIBUTE_NORMAL = 0x80; #region win32 API [DllImport("kernel32.dll ")] private static extern int CreateFile( string lpFileName, uint dwDesiredAccess, int dwShareMode, int lpSecurityAttributes, int dwCreationDisposition, uint dwFlagsAndAttributes, int hTemplateFile ); [DllImport("kernel32.dll ")] private static extern bool WriteFile( int hFile, byte[] lpBuffer, int nNumberOfBytesToWrite, ref int lpNumberOfBytesWritten, int lpOverlapped ); [DllImport("kernel32.dll ")] private static extern bool DefineDosDevice( int dwFlags, string lpDeviceName, string lpTargetPath); [DllImport("kernel32.dll ")] private static extern bool CloseHandle( int hObject ); [DllImport("kernel32.dll ")] private static extern bool ReadFile( int hFile, byte[] lpBuffer, int nNumberOfBytesToRead, ref int lpNumberOfBytesRead, int lpOverlapped ); #endregion public Form1() { InitializeComponent(); } private void button1_Click(object sender, EventArgs e) { int iHandle = -1; try { int i = 0; //创建实例 DefineDosDevice(0x00000001, "LptPortName",@"\Device\Parallel0"); iHandle = CreateFile(@"\\.\LptPortName",GENERIC_READ | GENERIC_WRITE, 0, 0, 3, FILE_ATTRIBUTE_NORMAL, 0); if (iHandle !=-1) { byte[] mybyte = new byte[3]{ 0x12, 0x14, 0x14 };//要发送的命令（16进制） WriteFile(iHandle, mybyte, mybyte.Length, ref i, 0); byte[] mybyte1 = new byte[3]; string content = String.Empty; int j = 0; ReadFile(iHandle, mybyte1, 3, ref j, 0); if (mybyte1 != null) { foreach(var tempByte in mybyte1) { content += tempByte.ToString(); } } MessageBox.Show(content);//获取的状态值 } else { MessageBox.Show("创建文件失败!"); } } catch(Exception ex) { MessageBox.Show(ex.Message); } finally { if (iHandle > 0) { CloseHandle(iHandle); } } } } }