用C#如何控制串口？

Question

用MSCOMM。OCX，但要装VC6，才能在WINFORM中用。

Answer 1

csharpindex有个例子，是用winapi的,你可以参考参考using System;
using System.Runtime.InteropServices;namespace JustinIO {
    class CommPort {        public int PortNum; 
        public int BaudRate;
        public byte ByteSize;
        public byte Parity; // 0-4=no,odd,even,,space 
        public byte StopBits; // 0,1,2 = 1, 1.5, 2 
        public int ReadTimeout;        //comm port win32 file handle
        private int hComm = -1;        public bool Opened = false;
         
        //win32 api constants
          private const uint GENERIC_READ = 0x80000000;
          private const uint GENERIC_WRITE = 0x40000000;
          private const int OPEN_EXISTING = 3;
          private const int INVALID_HANDLE_VALUE = -1;        [StructLayout(LayoutKind.Sequential)]
        public struct DCB {
            //taken from c struct in platform sdk 
            public int DCBlength;           // sizeof(DCB) 
            public int BaudRate;            // current baud rate
            /* these are the c struct bit fields, bit twiddle flag to set
            public int fBinary;          // binary mode, no EOF check 
            public int fParity;          // enable parity checking 
            public int fOutxCtsFlow;      // CTS output flow control 
            public int fOutxDsrFlow;      // DSR output flow control 
            public int fDtrControl;       // DTR flow control type 
            public int fDsrSensitivity;   // DSR sensitivity 
            public int fTXContinueOnXoff; // XOFF continues Tx 
            public int fOutX;          // XON/XOFF out flow control 
            public int fInX;           // XON/XOFF in flow control 
            public int fErrorChar;     // enable error replacement 
            public int fNull;          // enable null stripping 
            public int fRtsControl;     // RTS flow control 
            public int fAbortOnError;   // abort on error 
            public int fDummy2;        // reserved 
            */
            public uint flags;
            public ushort wReserved;          // not currently used 
            public ushort XonLim;             // transmit XON threshold 
            public ushort XoffLim;            // transmit XOFF threshold 
            public byte ByteSize;           // number of bits/byte, 4-8 
            public byte Parity;             // 0-4=no,odd,even,,space 
            public byte StopBits;           // 0,1,2 = 1, 1.5, 2 
            public char XonChar;            // Tx and Rx XON character 
            public char XoffChar;           // Tx and Rx XOFF character 
            public char ErrorChar;          // error replacement character 
            public char EofChar;            // end of input character 
            public char EvtChar;            // received event character 
            public ushort wReserved1;         // reserved; do not use 
        }        [StructLayout(LayoutKind.Sequential)]
        private struct COMMTIMEOUTS {
          public int ReadIntervalTimeout; 
          public int ReadTotalTimeoutMultiplier; 
          public int ReadTotalTimeoutConstant; 
          public int WriteTotalTimeoutMultiplier; 
          public int WriteTotalTimeoutConstant; 
        }             [StructLayout(LayoutKind.Sequential)]
        private struct OVERLAPPED { 
            public int  Internal; 
            public int  InternalHigh; 
            public int  Offset; 
            public int  OffsetHigh; 
            public int hEvent; 
        }        [DllImport("kernel32.dll")]
        private static extern int CreateFile(
          string lpFileName,                         // file name
          uint dwDesiredAccess,                      // access mode
          int dwShareMode,                          // share mode
          int lpSecurityAttributes, // SD
          int dwCreationDisposition,                // how to create
          int dwFlagsAndAttributes,                 // file attributes
          int hTemplateFile                        // handle to template file
        );
        [DllImport("kernel32.dll")]
        private static extern bool GetCommState(
          int hFile,  // handle to communications device
          ref DCB lpDCB    // device-control block
        );
        [DllImport("kernel32.dll")]
        private static extern bool BuildCommDCB(
          string lpDef,  // device-control string
          ref DCB lpDCB     // device-control block
        );
        [DllImport("kernel32.dll")]
        private static extern bool SetCommState(
          int hFile,  // handle to communications device
          ref DCB lpDCB    // device-control block
        );

Answer 2

[DllImport("kernel32.dll")]
        private static extern bool GetCommTimeouts(
          int hFile,                  // handle to comm device
          ref COMMTIMEOUTS lpCommTimeouts  // time-out values
        );
        [DllImport("kernel32.dll")]
        private static extern bool SetCommTimeouts(
          int hFile,                  // handle to comm device
          ref COMMTIMEOUTS lpCommTimeouts  // time-out values
        );
        [DllImport("kernel32.dll")]
        private static extern bool ReadFile(
          int hFile,                // handle to file
          byte[] lpBuffer,             // data buffer
          int nNumberOfBytesToRead,  // number of bytes to read
          ref int lpNumberOfBytesRead, // number of bytes read
          ref OVERLAPPED lpOverlapped    // overlapped buffer
        );
        [DllImport("kernel32.dll")]
        private static extern bool WriteFile(
          int hFile,                    // handle to file
          byte[] lpBuffer,                // data buffer
          int nNumberOfBytesToWrite,     // number of bytes to write
          ref int lpNumberOfBytesWritten,  // number of bytes written
          ref OVERLAPPED lpOverlapped        // overlapped buffer
        );
        [DllImport("kernel32.dll")]
        private static extern bool CloseHandle(
          int hObject   // handle to object
        );
        [DllImport("kernel32.dll")]
        private static extern uint GetLastError();        public void Open() {
         
         DCB dcbCommPort = new DCB();
         COMMTIMEOUTS ctoCommPort = new COMMTIMEOUTS();
         
         
          // OPEN THE COMM PORT.
          hComm = CreateFile("COM" + PortNum ,GENERIC_READ | GENERIC_WRITE,0, 0,OPEN_EXISTING,0,0);          // IF THE PORT CANNOT BE OPENED, BAIL OUT.
          if(hComm == INVALID_HANDLE_VALUE) {
                  throw(new ApplicationException("Comm Port Can Not Be Opened"));
          }          // SET THE COMM TIMEOUTS.          GetCommTimeouts(hComm,ref ctoCommPort);
          ctoCommPort.ReadTotalTimeoutConstant = ReadTimeout;
          ctoCommPort.ReadTotalTimeoutMultiplier = 0;
          ctoCommPort.WriteTotalTimeoutMultiplier = 0;
          ctoCommPort.WriteTotalTimeoutConstant = 0;
          SetCommTimeouts(hComm,ref ctoCommPort);          // SET BAUD RATE, PARITY, WORD SIZE, AND STOP BITS.
          GetCommState(hComm, ref dcbCommPort);
          dcbCommPort.BaudRate=BaudRate;
          dcbCommPort.flags=0;
          //dcb.fBinary=1;
          dcbCommPort.flags|=1;
          if (Parity>0)
          {
               //dcb.fParity=1
              dcbCommPort.flags|=2;
          }
          dcbCommPort.Parity=Parity;
          dcbCommPort.ByteSize=ByteSize;
          dcbCommPort.StopBits=StopBits;
          if (!SetCommState(hComm, ref dcbCommPort))
          {
             //uint ErrorNum=GetLastError();
             throw(new ApplicationException("Comm Port Can Not Be Opened"));
          }
          //unre to see if setting took correctly
          //DCB dcbCommPort2 = new DCB();
          //GetCommState(hComm, ref dcbCommPort2);
          Opened = true;        }        public void Close() {
            if (hComm!=INVALID_HANDLE_VALUE) {
                CloseHandle(hComm);
            }
        }        public byte[] Read(int NumBytes) {
            byte[] BufBytes;
            byte[] OutBytes;
            BufBytes = new byte[NumBytes];
            if (hComm!=INVALID_HANDLE_VALUE) {
                OVERLAPPED ovlCommPort = new OVERLAPPED();
                int BytesRead=0;
                ReadFile(hComm,BufBytes,NumBytes,ref BytesRead,ref ovlCommPort);
                OutBytes = new byte[BytesRead];
                Array.Copy(BufBytes,OutBytes,BytesRead);
            } 
            else {
                throw(new ApplicationException("Comm Port Not Open"));
            }
            return OutBytes;
        }        public void Write(byte[] WriteBytes) {
            if (hComm!=INVALID_HANDLE_VALUE) {
                OVERLAPPED ovlCommPort = new OVERLAPPED();
                int BytesWritten = 0;
                WriteFile(hComm,WriteBytes,WriteBytes.Length,ref BytesWritten,ref ovlCommPort);
            }
            else {
                throw(new ApplicationException("Comm Port Not Open"));
            }
        }
    }    class HexCon {
    //converter hex string to byte and byte to hex string
        public static string ByteToString(byte[] InBytes) {
            string StringOut="";
            foreach (byte InByte in InBytes) {
                StringOut=StringOut + String.Format("{0:X2} ",InByte);
            }
            return StringOut; 
        }
        public static byte[] StringToByte(string InString) {
            string[] ByteStrings;
            ByteStrings = InString.Split(" ".ToCharArray());
            byte[] ByteOut;
            ByteOut = new byte[ByteStrings.Length-1];
            for (int i = 0;i==ByteStrings.Length-1;i++) {
                ByteOut[i] = Convert.ToByte(("0x" + ByteStrings[i]));
            } 
            return ByteOut;
        }
    }
}