C# 串口读写程序 串口通讯示例源码

【实例截图】

【核心代码】

using System;
using System.Runtime.InteropServices;

namespace JustinIO
{
    public class CommPort
    {

        public string PortNum;
        public int BaudRate;
        public byte ByteSize;
        public byte Parity; // 0-4=no,odd,even,mark,space 
        public byte StopBits; // 0,1,2 = 1, 1.5, 2 
        public int ReadTimeout;

        //comm port win32 file handle
        private int hComm = -1;

        public int Tran;//10,50,100,500,1000

        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;            // 指定当前波特率 current baud rate
            // these are the c struct bit fields, bit twiddle flag to set
            public int fBinary;          // 指定是否允许二进制模式,在windows95中必须主TRUE binary mode, no EOF check 
            public int fParity;          // 指定是否允许奇偶校验 enable parity checking 
            public int fOutxCtsFlow;      // 指定CTS是否用于检测发送控制，当为TRUE是CTS为OFF，发送将被挂起。 CTS output flow control 
            public int fOutxDsrFlow;      // 指定CTS是否用于检测发送控制 DSR output flow control 
            public int fDtrControl;       // DTR_CONTROL_DISABLE值将DTR置为OFF, DTR_CONTROL_ENABLE值将DTR置为ON, DTR_CONTROL_HANDSHAKE允许DTR"握手" DTR flow control type 
            public int fDsrSensitivity;   // 当该值为TRUE时DSR为OFF时接收的字节被忽略 DSR sensitivity 
            public int fTXContinueOnXoff; // 指定当接收缓冲区已满,并且驱动程序已经发送出XoffChar字符时发送是否停止。TRUE时，在接收缓冲区接收到缓冲区已满的字节XoffLim且驱动程序已经发送出XoffChar字符中止接收字节之后，发送继续进行。　FALSE时，在接收缓冲区接收到代表缓冲区已空的字节XonChar且驱动程序已经发送出恢复发送的XonChar之后，发送继续进行。XOFF continues Tx 
            public int fOutX;          // TRUE时，接收到XoffChar之后便停止发送接收到XonChar之后将重新开始 XON/XOFF out flow control 
            public int fInX;           // TRUE时，接收缓冲区接收到代表缓冲区满的XoffLim之后，XoffChar发送出去接收缓冲区接收到代表缓冲区空的XonLim之后，XonChar发送出去 XON/XOFF in flow control 
            public int fErrorChar;     // 该值为TRUE且fParity为TRUE时，用ErrorChar 成员指定的字符代替奇偶校验错误的接收字符 enable error replacement 
            public int fNull;          // eTRUE时，接收时去掉空（0值）字节 enable null stripping 
            public int fRtsControl;     // RTS flow control 
            /*RTS_CONTROL_DISABLE时,RTS置为OFF
            RTS_CONTROL_ENABLE时, RTS置为ON
        RTS_CONTROL_HANDSHAKE时,
        当接收缓冲区小于半满时RTS为ON
            当接收缓冲区超过四分之三满时RTS为OFF
        RTS_CONTROL_TOGGLE时,
        当接收缓冲区仍有剩余字节时RTS为ON ,否则缺省为OFF*/

            public int fAbortOnError;   // TRUE时,有错误发生时中止读和写操作 abort on error 
            public int fDummy2;        // 未使用 reserved 

            public uint flags;
            public ushort wReserved;          // 未使用,必须为0 not currently used 
            public ushort XonLim;             // 指定在XON字符发送这前接收缓冲区中可允许的最小字节数 transmit XON threshold 
            public ushort XoffLim;            // 指定在XOFF字符发送这前接收缓冲区中可允许的最小字节数 transmit XOFF threshold 
            public byte ByteSize;           // 指定端口当前使用的数据位	number of bits/byte, 4-8 
            public byte Parity;             // 指定端口当前使用的奇偶校验方法,可能为:EVENPARITY,MARKPARITY,NOPARITY,ODDPARITY  0-4=no,odd,even,mark,space 
            public byte StopBits;           // 指定端口当前使用的停止位数,可能为:ONESTOPBIT,ONE5STOPBITS,TWOSTOPBITS  0,1,2 = 1, 1.5, 2 
            public char XonChar;            // 指定用于发送和接收字符XON的值 Tx and Rx XON character 
            public char XoffChar;           // 指定用于发送和接收字符XOFF值 Tx and Rx XOFF character 
            public char ErrorChar;          // 本字符用来代替接收到的奇偶校验发生错误时的值 error replacement character 
            public char EofChar;            // 当没有使用二进制模式时,本字符可用来指示数据的结束 end of input character 
            public char EvtChar;            // 当接收到此字符时,会产生一个事件 received event character 
            public ushort wReserved1;         // 未使用 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 ,                         // 要打开的串口名称
          uint dwDesiredAccess ,                      // 指定串口的访问方式，一般设置为可读可写方式
          int dwShareMode ,                          // 指定串口的共享模式，串口不能共享，所以设置为0
          int lpSecurityAttributes , // 设置串口的安全属性，WIN9X下不支持，应设为NULL
          int dwCreationDisposition ,                // 对于串口通信，创建方式只能为OPEN_EXISTING
          int dwFlagsAndAttributes ,                 // 指定串口属性与标志，设置为FILE_FLAG_OVERLAPPED(重叠I/O操作)，指定串口以异步方式通信
          int hTemplateFile                        // 对于串口通信必须设置为NULL
        );
        [DllImport ( "kernel32.dll" )]
        private static extern bool GetCommState (
          int hFile ,  //通信设备句柄
          ref DCB lpDCB    // 设备控制块DCB
        );
        [DllImport ( "kernel32.dll" )]
        private static extern bool BuildCommDCB (
          string lpDef ,  // 设备控制字符串
          ref DCB lpDCB     // 设备控制块
        );
        [DllImport ( "kernel32.dll" )]
        private static extern bool SetCommState (
          int hFile ,  // 通信设备句柄
          ref DCB lpDCB    // 设备控制块
        );
        [DllImport ( "kernel32.dll" )]
        private static extern bool GetCommTimeouts (
          int hFile ,                  // 通信设备句柄 handle to comm device
          ref COMMTIMEOUTS lpCommTimeouts  // 超时时间 time-out values
        );
        [DllImport ( "kernel32.dll" )]
        private static extern bool SetCommTimeouts (
          int hFile ,                  // 通信设备句柄 handle to comm device
          ref COMMTIMEOUTS lpCommTimeouts  // 超时时间 time-out values
        );
        [DllImport ( "kernel32.dll" )]
        private static extern bool ReadFile (
          int hFile ,                // 通信设备句柄 handle to file
          byte [ ] lpBuffer ,             // 数据缓冲区 data buffer
          int nNumberOfBytesToRead ,  // 多少字节等待读取 number of bytes to read
          ref int lpNumberOfBytesRead , // 读取多少字节 number of bytes read
          ref OVERLAPPED lpOverlapped    // 溢出缓冲区 overlapped buffer
        );
        [DllImport ( "kernel32.dll" )]
        private static extern bool WriteFile (
          int hFile ,                    // 通信设备句柄 handle to file
          byte [ ] lpBuffer ,                // 数据缓冲区 data buffer
          int nNumberOfBytesToWrite ,     // 多少字节等待写入 number of bytes to write
          ref int lpNumberOfBytesWritten ,  // 已经写入多少字节 number of bytes written
          ref OVERLAPPED lpOverlapped        // 溢出缓冲区 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 ( );

            // 打开串口 OPEN THE COMM PORT.
            hComm = CreateFile ( PortNum , GENERIC_READ | GENERIC_WRITE , 0 , 0 , OPEN_EXISTING , 0 , 0 );
            // 如果串口没有打开，就打开 IF THE PORT CANNOT BE OPENED, BAIL OUT.
            if ( hComm == INVALID_HANDLE_VALUE )
            {
                throw ( new ApplicationException ( "非法操作，不能打开串口！" ) );
            }

            // 设置通信超时时间 SET THE COMM TIMEOUTS.
            GetCommTimeouts ( hComm , ref ctoCommPort );
            ctoCommPort.ReadTotalTimeoutConstant = ReadTimeout;
            ctoCommPort.ReadTotalTimeoutMultiplier = 0;
            ctoCommPort.WriteTotalTimeoutMultiplier = 0;
            ctoCommPort.WriteTotalTimeoutConstant = 0;
            SetCommTimeouts ( hComm , ref ctoCommPort );

            // 设置串口 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 ( "非法操作，不能打开串口！" ) );
            }
            //unremark 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 ( "串口未打开！" ) );
            }
            return OutBytes;
        }

        public int Write ( byte [ ] WriteBytes )
        {
            int BytesWritten = 0;
            if ( hComm != INVALID_HANDLE_VALUE )
            {
                OVERLAPPED ovlCommPort = new OVERLAPPED ( );
                WriteFile ( hComm , WriteBytes , WriteBytes.Length , ref BytesWritten , ref ovlCommPort );
            }
            else
            {
                throw ( new ApplicationException ( "串口未打开！" ) );
            }
            return BytesWritten;
        }
    }

    class HexCon
    {
        // 把十六进制字符串转换成字节型和把字节型转换成十六进制字符串 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;
        }
    }
}