C++连接串口方式（MFC版本）(简单版本)

ComSerialPort.h

/*_________________________串口________________________________*/

class Com_SerialPort
{
    
    
public:
	Com_SerialPort();
	Com_SerialPort(int port, int baudRate, int byteSize, int parity, int stopBits);
	~Com_SerialPort();
public:
	bool Connect(bool bMutex = false) override;
	void DisConnect(bool bMutex = false) override;
	bool clearBuf_c();
	bool recvBuf_c(char* pStr, int& len, int waitTimeMS = 0) override;
	bool sendBuf_c(char const *pStr, const int& len) override;
private:
	BOOL setReadTime(DWORD time);
private:
	HANDLE m_hCom;
	DCB m_dcb;
	COMMTIMEOUTS m_timeOuts;
};

ComSerialPort.cpp

/*_________________________串口________________________________*/

Com_SerialPort::Com_SerialPort()
{
    
    
	m_dcb.BaudRate = 9600;			//波特率为9600
	m_dcb.ByteSize = 8;				//每个字节有8位
	m_dcb.Parity = NOPARITY;		//无奇偶校验位
	m_dcb.StopBits = ONESTOPBIT;	//1个停止位
	m_typeName = "串口";

	//设定读超时
	m_timeOuts.ReadIntervalTimeout = 100;//读间隔超时
	m_timeOuts.ReadTotalTimeoutMultiplier = 0;//读时间系数 
	m_timeOuts.ReadTotalTimeoutConstant = 1000;//读时间常量 
	//设定写超时
	m_timeOuts.WriteTotalTimeoutMultiplier = 500; // 写时间系数 
	m_timeOuts.WriteTotalTimeoutConstant = 2000;//写时间常量 
}

Com_SerialPort::Com_SerialPort(int port, int baudRate, int byteSize, int parity, int stopBits)
{
    
    
	m_Port = port;
	m_dcb.BaudRate = baudRate;			//波特率为9600;
	m_dcb.ByteSize = byteSize;			//每个字节有8位;
	m_dcb.Parity = parity;				//无奇偶校验位;
	m_dcb.StopBits = stopBits;			//1个停止位;
	m_typeName = "串口";
	//设定读超时
	m_timeOuts.ReadIntervalTimeout = 100;//读间隔超时
	m_timeOuts.ReadTotalTimeoutMultiplier = 0;//读时间系数 
	m_timeOuts.ReadTotalTimeoutConstant = 1000;//读时间常量 
	//设定写超时
	m_timeOuts.WriteTotalTimeoutMultiplier = 500; // 写时间系数 
	m_timeOuts.WriteTotalTimeoutConstant = 2000;//写时间常量 
}

Com_SerialPort::~Com_SerialPort()
{
    
    
}

bool Com_SerialPort::Connect(bool bMutex)
{
    
    
	QMutexLocker locker(&m_Mutex);
	DisConnect(false);
	char str_c[256];
	memset(str_c, '\0', 256);
	snprintf(str_c, sizeof(str_c), "COM%d", m_Port);
	std::string ComStr(str_c);
	WCHAR wComName[128];
	memset(wComName, '\0', sizeof(wComName));
	MultiByteToWideChar(CP_ACP, 0, ComStr.c_str(), -1, wComName, sizeof(wComName) / sizeof(wComName[0]));

	m_hCom = CreateFile(wComName,//COM1口
		GENERIC_READ | GENERIC_WRITE, //允许读和写;
		0, //独占方式;
		NULL,
		OPEN_EXISTING, //打开而不是创建;
		0, //同步方式;
		NULL);

	//if (hCom1 == (HANDLE)-1)
	if (m_hCom == INVALID_HANDLE_VALUE)
	{
    
    
		printf("打开COM失败!\n");
		m_bConnectOK = false;
		return false;
	}
	SetupComm(m_hCom, CHAR_LEN, CHAR_LEN); //输入缓冲区和输出缓冲区的大小都是1024

	//设定读超时
	BOOL RTN = SetCommTimeouts(m_hCom, &m_timeOuts); //设置超时

	DCB dcb;
	GetCommState(m_hCom, &dcb);
	dcb.BaudRate = m_dcb.BaudRate;		//波特率为9600
	dcb.ByteSize = m_dcb.ByteSize;		//每个字节有8位
	dcb.Parity = m_dcb.Parity;			//无奇偶校验位
	dcb.StopBits = m_dcb.StopBits;		//1个停止位
	SetCommState(m_hCom, &dcb);
	m_bConnectOK = true;
	return true;
}

void Com_SerialPort::DisConnect(bool bMutex)
{
    
    
	if (bMutex)m_Mutex.lock();
	if (m_hCom != INVALID_HANDLE_VALUE)
	{
    
    
		CloseHandle(m_hCom);
		m_hCom = INVALID_HANDLE_VALUE;
		m_bConnectOK = false;
	}
	if (bMutex)m_Mutex.unlock();
}

bool Com_SerialPort::clearBuf_c()
{
    
    
	QMutexLocker locker(&m_Mutex);
	setReadTime(200);
	DWORD initTime = GetTickCount();
	do
	{
    
    
		DWORD readsize = 0;
		ReadFile(m_hCom, m_recvBuffer, CHAR_LEN, &readsize, NULL);
		if (readsize <= 0)
			return true;
		if (abs(int(GetTickCount() - initTime)) > 1000)
			return false;
	} while (1);
	return false;
}

bool Com_SerialPort::recvBuf_c(char * pStr, int & len, int waitTimeMS)
{
    
    
	QMutexLocker locker(&m_Mutex);
	DWORD readsize = 0;
	setReadTime(waitTimeMS);
	ReadFile(m_hCom, pStr, CHAR_LEN, &readsize, NULL);
	len = readsize;
	return readsize>0;
}

bool Com_SerialPort::sendBuf_c(char const * pStr, const int & len)
{
    
    
	QMutexLocker locker(&m_Mutex);
	BOOL rtn = WriteFile(m_hCom, pStr, len, NULL, NULL);
	return rtn != 0;
}

BOOL Com_SerialPort::setReadTime(DWORD time)
{
    
    
	if (time != m_timeOuts.ReadTotalTimeoutConstant)
	{
    
    
		//读时间常量
		m_timeOuts.ReadTotalTimeoutConstant = time;
		return SetCommTimeouts(m_hCom, &m_timeOuts); //设置超时
	}
	return 0;
}