基于Win32的 串口通信操作类

// CommPort.cpp: implementation of the CCommPort class. // ////////////////////////////////////////////////////////////////////// #include "stdafx.h" #include "CommPort.h" #ifdef _DEBUG #undef THIS_FILE static char THIS_FILE[]=__FILE__; #define new DEBUG_NEW #endif ////////////////////////////////////////////////////////////////////// // Construction/Destruction ////////////////////////////////////////////////////////////////////// CCommPort::CCommPort() { m_hComm = NULL; m_pThread= NULL; m_bConnect = FALSE; m_dwRInterval= MAXDWORD; m_dwInQueue = 2048; m_dwOutQueue = 2048; HandSetEvent(); } CCommPort::~CCommPort() { if(m_bConnect) ClosePort(); if(m_hPostMsgEvent) CloseHandle(m_hPostMsgEvent); if(m_olRead.hEvent) CloseHandle(m_olRead.hEvent); if(m_olWrite.hEvent) CloseHandle(m_olWrite.hEvent); } BOOL CCommPort::OpenPort(CString sPortName,HWND hWnd) { COMMTIMEOUTS TimeOuts; if(IsWindow(hWnd)) m_hTermWnd=hWnd; //保存传递来的WM_COMMNOTIFY消息（即读取与处理数据消息）的所在窗口句柄 else { AfxMessageBox("传递的窗口句柄无效！"); return FALSE; } if(m_bConnect) //判断串口是否已打开 { AfxMessageBox("串口已打开！"); return FALSE; } else { m_hComm=CreateFile(sPortName, GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, //以重叠I/O方式打开串口 FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED, NULL); if(m_hComm==INVALID_HANDLE_VALUE) { AfxMessageBox("串口已被占用或串口不存在!"); return FALSE; } SetupComm(m_hComm,m_dwInQueue,m_dwOutQueue); //设置串口接收和发送缓冲区的大小 ：最大 SetCommMask(m_hComm,EV_RXCHAR); //设置串口事件 ： 输入缓冲区有新字符 // 把间隔超时设为最大，把总超时设为 0 将导致 ReadFile 立即返回并完成操作 TimeOuts.ReadIntervalTimeout=m_dwRInterval; TimeOuts.ReadTotalTimeoutMultiplier=0; TimeOuts.ReadTotalTimeoutConstant=0; // 设置写超时以指定 WriteComm 成员函数中的GetOverlappedResult 函数的等待时间 TimeOuts.WriteTotalTimeoutMultiplier=50; TimeOuts.WriteTotalTimeoutConstant=2000; SetCommTimeouts(m_hComm, &TimeOuts); //设置超时 } return TRUE; } BOOL CCommPort::SetupPort(int nBaud, int nParity, int nDataBits, int nStop) { DCB dcb; if(!GetCommState(m_hComm,&dcb)) { CloseHandle(m_hComm); //关闭串口 AfxMessageBox("配置串口错误\r请检查参数设置"); return FALSE; } dcb.BaudRate= nBaud; //设置参数 dcb.ByteSize= nDataBits; switch(nParity) { case 0: dcb.Parity = NOPARITY; break; case 1: dcb.Parity = ODDPARITY; break; case 2: dcb.Parity = EVENPARITY; break; case 3: dcb.Parity = MARKPARITY; break; case 4: dcb.Parity = SPACEPARITY; break; default: break; } switch(nStop) { case 0: dcb.StopBits = ONESTOPBIT; break; case 1: dcb.StopBits = ONE5STOPBITS; break; case 2: dcb.StopBits = TWOSTOPBITS; break; default: break; } if(!SetCommState(m_hComm,&dcb)) //配置串口 { CloseHandle(m_hComm); //关闭串口 AfxMessageBox("配置串口错误\r请检查参数设置"); return FALSE; } PurgeComm(m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT); //终止所有后台读写操作并清空缓冲区 return TRUE; } DWORD CCommPort::WritePort(int *buf,DWORD dwLength) { if(!m_bConnect) { AfxMessageBox("串口未连接，请连接！"); return 0; } BOOL bWriteState; //写入是否成功 COMSTAT ComStat; //包含了通信设备的信息 DWORD dwErrorFlags; //错误标示 DWORD length=dwLength; //写入字符长度 ClearCommError(m_hComm,&dwErrorFlags,&ComStat); //清空错误标示，报告错误 if(dwErrorFlags>0) { AfxMessageBox("写串口错误！"); PurgeComm(m_hComm,PURGE_TXABORT|PURGE_TXCLEAR); //清空缓冲区 return 0; } bWriteState=WriteFile(m_hComm,buf,length,&length,&m_olWrite); //写入数据 if(!bWriteState) { if(GetLastError()==ERROR_IO_PENDING) //判断是否因为写操作未完成 { GetOverlappedResult(m_hComm,&m_olWrite,&length,TRUE); //等待写入完成 } else { AfxMessageBox("写串口错误！"); return 0; } } return length; } DWORD CCommPort::ReadPort(int *buf, DWORD dwLength) { if(!m_bConnect) { AfxMessageBox("串口未连接！"); return 0; } DWORD length=0; COMSTAT ComStat; DWORD dwErrorFlags; ClearCommError(m_hComm,&dwErrorFlags,&ComStat); //获得当前通信串口状态，来确定接收缓区中处于等待的字节数。 length=min(dwLength, ComStat.cbInQue); //选择最小长度进行读取 if(!ReadFile(m_hComm,buf,length,&length,&m_olRead)) //如果串口读取成功，数据会存储在buf数组中 { AfxMessageBox("读串口错误\r参数传递是否正确"); return 0; } return length; //返回实际读取字符的长度 } void CCommPort::ClosePort() { if(!m_bConnect) return; m_bConnect=FALSE; SetEvent(m_hPostMsgEvent); //结束 CommProc 线程中 WaitSingleObject 函数的等待 SetCommMask(m_hComm,0); //结束 CommProc 线程中 WaitCommEvent 的等待 WaitForSingleObject(m_pThread->m_hThread,INFINITE); //等待辅助线程终止 m_pThread=NULL; //清空 PurgeComm(m_hComm,PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT);//终止所有后台读写操作并清空缓冲区 CloseHandle(m_hComm); //关闭串口 } BOOL CCommPort::CreateThread() { m_pThread=AfxBeginThread(CommProcFun,this,THREAD_PRIORITY_NORMAL,0,CREATE_SUSPENDED,NULL); //创建工作者线程，并挂起 if(m_pThread==NULL) { CloseHandle(m_hComm); //关闭串口 AfxMessageBox("线程创建失败"); return FALSE; } m_bConnect=TRUE; //标示串口已成功连接 m_pThread->ResumeThread(); //恢复线程 return TRUE; } BOOL CCommPort::HandSetEvent() { // 为 WM_COMMNOTIFY 消息创建事件对象，手工重置，初始化为有信号的 if((m_hPostMsgEvent=CreateEvent(NULL, TRUE, TRUE, NULL))==NULL) return FALSE; memset(&m_olRead, 0, sizeof(OVERLAPPED)); memset(&m_olWrite,0, sizeof(OVERLAPPED)); // 为重叠读创建事件对象，手工重置，初始化为无信号的 if((m_olRead.hEvent=CreateEvent(NULL, TRUE, FALSE, NULL))==NULL) return FALSE; // 为重叠写创建事件对象，手工重置，初始化为无信号的 if((m_olWrite.hEvent=CreateEvent(NULL, TRUE, FALSE, NULL))==NULL) return FALSE; return TRUE; } /************************************************************************/ /* 工作者线程，监视串口 */ /************************************************************************/ UINT CommProcFun(LPVOID pParam) { OVERLAPPED ol; COMSTAT ComStat; DWORD dwMask=0,dwTrans; DWORD dwErrorFlags; CCommPort *pCommPort=(CCommPort*)pParam; //获得串口类对象地址 memset(&ol,0,sizeof(OVERLAPPED)); ol.hEvent=CreateEvent(NULL,TRUE,FALSE,NULL); //设置事件 if(ol.hEvent==NULL) { AfxMessageBox("设置事件对象失败"); return (UINT)-1; } while(pCommPort->m_bConnect) { ClearCommError(pCommPort->m_hComm,&dwErrorFlags,&ComStat); //获得缓冲区字节长度 if(ComStat.cbInQue) //如果不为0 { WaitForSingleObject(pCommPort->m_hPostMsgEvent,INFINITE); //无限等待WM_COMMNOTIFY消息处理完成 ResetEvent(pCommPort->m_hPostMsgEvent); //设置事件为无信号 PostMessage(pCommPort->m_hTermWnd,WM_COMMNOTIFY,EV_RXCHAR,0); //发送读取与处理消息 // SendMessage(pCommPort->m_hTermWnd,WM_COMMNOTIFY,EV_RXCHAR,0); continue; } //跳出本次循环 if(!WaitCommEvent(pCommPort->m_hComm,&dwMask,&ol)) //如果缓冲区无字节，进行重叠操作 { if(GetLastError()==ERROR_IO_PENDING) GetOverlappedResult(pCommPort->m_hComm,&ol,&dwTrans,TRUE); //无限等待通信事件发生 else { CloseHandle(ol.hEvent); return (UINT)-1; } } } Close