在网上找的代码，然后修改的。
//Comm.cs using System; using System.Runtime.InteropServices; namespace Comm { public class myCom { #region WINAPI常量 /// /// 写标志 /// private const uint GENERIC_READ = 0x80000000; /// /// 读标志 /// private const uint GENERIC_WRITE = 0x40000000; /// /// 打开已存在 /// private const int OPEN_EXISTING = 3; /// /// 无效句柄 /// private const int INVALID_HANDLE_VALUE = -1; #endregion #region 成员变量 /// /// 端口名称(COM1,COM2...COM4...) /// public int PortNum; /// /// 波特率9600 /// public int BaudRate; /// /// 数据位4-8 /// public byte ByteSize; /// /// 奇偶校验0-4=no,odd,even,mark,space /// public byte Parity; /// /// 停止位 /// public byte StopBits; // 0,1,2 = 1, 1.5, 2 /// /// 超时长 /// public int ReadTimeout; /// /// COM口句柄 /// private int hComm = INVALID_HANDLE_VALUE; /// /// 串口是否已经打开 /// public bool Opened = false; #endregion /// /// 设备控制块结构体类型 /// [StructLayout(LayoutKind.Sequential)] public struct DCB { /// /// DCB长度 /// public int DCBlength; /// /// 指定当前波特率 /// public int BaudRate; /// /// 指定是否允许二进制模式 /// public int fBinary; /// /// 指定是否允许奇偶校验 /// public int fParity; /// /// 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。 /// public int fOutxCtsFlow; /// /// 指定CTS是否用于检测发送控制 /// public int fOutxDsrFlow; /// /// 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" /// public int fDtrControl; /// /// 当该值为TRUE时DSR为OFF时接收的字节被忽略 /// public int fDsrSensitivity; /// /// 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 fTXContinueOnXoff; /// /// 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 fOutX; /// /// 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 fInX; /// /// 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 fErrorChar; /// /// eTRUE时，接收时去掉空（0值）字节 enable null stripping /// public int fNull; /// /// 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 fRtsControl; /// /// TRUE时,有错误发生时中止读和写操作 abort on error /// public int fAbortOnError; /// /// 未使用 /// public int fDummy2; /// /// 标志位 /// public uint flags; /// /// 未使用,必须为0 /// public ushort wReserved; /// /// 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 /// public ushort XonLim; /// /// 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 /// public ushort XoffLim; /// /// 指定端口当前使用的数据位 /// public byte ByteSize; /// /// 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 Parity; /// /// 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 byte StopBits; /// /// 指定用于发送和接收字符XON的值 Tx and Rx XON character /// public char XonChar; /// /// 指定用于发送和接收字符XOFF值 Tx and Rx XOFF character /// public char XoffChar; /// /// 本字符用来代替接收到的奇偶校验发生错误时的值 /// public char ErrorChar; /// /// 当没有使用二进制模式时,本字符可用来指示数据的结束 /// public char EofChar; /// /// 当接收到此字符时,会产生一个事件 /// public char EvtChar; /// /// 未使用 /// public ushort wReserved1; } /// /// 串口超时时间结构体类型 /// [StructLayout(LayoutKind.Sequential)] private struct COMMTIMEOUTS { public int ReadIntervalTimeout; public int ReadTotalTimeoutMultiplier; public int ReadTotalTimeoutConstant; public int WriteTotalTimeoutMultiplier; public int WriteTotalTimeoutConstant; } /// /// 湓出缓冲区结构体类型 /// [StructLayout(LayoutKind.Sequential)] private struct OVERLAPPED { public int Internal; public int InternalHigh; public int Offset; public int OffsetHigh; public int hEvent; } /// /// 打开串口 /// /// 要打开的串口名称 /// 指定串口的访问方式，一般设置为可读可写方式 /// 指定串口的共享模式，串口不能共享，所以设置为0 /// 设置串口的安全属性，WIN9X下不支持，应设为NULL /// 对于串口通信，创建方式只能为OPEN_EXISTING /// 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 /// 对于串口通信必须设置为NULL [DllImport("kernel32.dll")] private static extern int CreateFile(string lpFileName, uint dwDesiredAccess, int dwShareMode, int lpSecurityAttributes, int dwCreationDisposition, int dwFlagsAndAttributes, int hTemplateFile); /// /// 得到串口状态 /// /// 通信设备句柄 /// 设备控制块DCB [DllImport("kernel32.dll")] private static extern bool GetCommState(int hFile, ref DCB lpDCB); /// /// 建立串口设备控制块 /// /// 设备控制字符串 /// 设备控制块 [DllImport("kernel32.dll")] private static extern bool BuildCommDCB(string lpDef, ref DCB lpDCB); /// /// 设置串口状态 /// /// 通信设备句柄 /// 设备控制块 [DllImport("kernel32.dll")] private static extern bool SetCommState(int hFile, ref DCB lpDCB); /// /// 读取串口超时时间 /// /// 通信设备句柄 /// 超时时间 [DllImport("kernel32.dll")] private static extern bool GetCommTimeouts(int hFile, ref COMMTIMEOUTS lpCommTimeouts); /// /// 设置串口超时时间 /// /// 通信设备句柄 /// 超时时间 [DllImport("kernel32.dll")] private static extern bool SetCommTimeouts(int hFile, ref COMMTIMEOUTS lpCommTimeouts); /// /// 读取串口数据 /// /// 通信设备句柄 /// 数据缓冲区 /// 多少字节等待读取 /// 读取多少字节 /// 溢出缓冲区 [DllImport("kernel32.dll")] private static extern bool ReadFile(int hFile, byte[] lpBuffer, int nNumberOfBytesToRead,ref int lpNumberOfBytesRead, ref OVERLAPPED lpOverlapped); /// /// 写串口数据 /// /// 通信设备句柄 /// 数据缓冲区 /// 多少字节等待写入 /// 已经写入多少字节 /// 溢出缓冲区 [DllImport("kernel32.dll")] private static extern bool WriteFile(int hFile, byte[] lpBuffer, int nNumberOfBytesToWrite,ref int lpNumberOfBytesWritten, ref OVERLAPPED lpOverlapped); [DllImport("kernel32.dll", SetLastError = true)] private static extern bool FlushFileBuffers(int hFile); [DllImport("kernel32.dll", SetLastError = true)] private static extern bool PurgeComm(int hFile, uint dwFlags); /// /// 关闭串口 /// /// 通信设备句柄 [DllImport("kernel32.dll")] private static extern bool CloseHandle(int hObject); /// /// 得到串口最后一次返回的错误 /// [DllImport("kernel32.dll")] private static extern uint GetLastError(); /// /// 建立与串口的连接 /// public bool Open() { DCB dcbCommPort = new DCB(); COMMTIMEOUTS ctoCommPort = new COMMTIMEOUTS(); // 打开串口 hComm = CreateFile("COM" + PortNum, GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0); if (hComm == INVALID_HANDLE_VALUE) { return false; } // 设置通信超时时间 GetCommTimeouts(hComm, ref ctoCommPort); ctoCommPort.ReadTotalTimeoutConstant = ReadTimeout; ctoCommPort.ReadTotalTimeoutMultiplier = 0; ctoCommPort.WriteTotalTimeoutMultiplier = 0; ctoCommPort.WriteTotalTimeoutConstant = 0; SetCommTimeouts(hComm, ref ctoCommPort); // 设置串口 GetCommState(hComm, ref dcbCommPort); dcbCommPort.fOutxCtsFlow = 524800; dcbCommPort.BaudRate = BaudRate; dcbCommPort.flags = 0; dcbCommPort.flags |= 1; if (Parity > 0) { dcbCommPort.flags |= 2; } dcbCommPort.Parity = Parity; dcbCommPort.ByteSize = ByteSize; dcbCommPort.StopBits = StopBits; dcbCommPort.fOutxCtsFlow = 524800; if (!SetCommState(hComm, ref dcbCommPort)) { return false; } Opened = true; return true; } /// /// 关闭串口,结束通讯 /// public bool Close() { if (hComm != INVALID_HANDLE_VALUE) { CloseHandle(hComm); Opened = false; return true; } return false; } /// /// 读取串口返回的数据 /// /// 数据长度 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); return OutBytes; } else { return new byte[0]; } } /// /// 清空COM口缓冲区数据 /// /// public bool ClearPortData() { if (hComm != INVALID_HANDLE_VALUE) { return PurgeComm(hComm, 0); } return false; } /// /// 向串口写数据 /// /// 数据数组 public int Write(byte[] WriteBytes) { bool result; if (hComm != INVALID_HANDLE_VALUE) { OVERLAPPED ovlCommPort = new OVERLAPPED(); int BytesWritten = 0; WriteFile(hComm, WriteBytes, WriteBytes.Length, ref BytesWritten, ref ovlCommPort); return BytesWritten; } else { return 0; } } } }
