pserialport.cpp

一个EVC写的关于串口通信的例子,使用modbus协议进行通信,希望对您有所帮助.

// PSerialPort.cpp: implementation of the CPSerialPort class.
//
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
//#include "SerialPort.h"
#include "PSerialPort.h"

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CPSerialPort::CPSerialPort()
{
	m_hComm=INVALID_HANDLE_VALUE;
	m_hReadThread=NULL;
	m_bReceiving=FALSE;
	m_nBufferSize=256; //缓冲大小
}

CPSerialPort::~CPSerialPort()
{
	ClosePort();
}

DWORD WINAPI CPSerialPort::ReadPortThread(LPVOID lpParameter)
{
	CPSerialPort* m_pSerial;

	m_pSerial=(CPSerialPort*)lpParameter;

	BOOL fReadState;
	DWORD dwLength;
	
	char* buf=new char[m_pSerial->m_nBufferSize];

	while((m_pSerial->m_hComm!=INVALID_HANDLE_VALUE)&&(m_pSerial->m_bReceiving))
	{		
		fReadState=ReadFile(m_pSerial->m_hComm,buf,m_pSerial->m_nBufferSize,&dwLength,NULL);
		if(!fReadState)
		{
			//AfxMessageBox(_T("无法从串口读取数据！"));
		}
		else
		{
			if(dwLength!=0)
			{
				//回送数据
				if(m_pSerial->m_lpDataArriveProc!=NULL)
				{
					m_pSerial->m_lpDataArriveProc(buf,dwLength,m_pSerial->m_dwUserData);
				}
			}
		}		
	}

	delete[] buf;

	return 0;
}

BOOL CPSerialPort::OpenPort(LPCTSTR Port,int BaudRate,int DataBits,int StopBits,int Parity,LPDataArriveProc proc,DWORD userdata)
{
	m_lpDataArriveProc=proc;
	m_dwUserData=userdata;

	if(m_hComm==INVALID_HANDLE_VALUE)
	{
		m_hComm=CreateFile(Port,GENERIC_READ|GENERIC_WRITE,0,0,OPEN_EXISTING,0,0);
		if(m_hComm==INVALID_HANDLE_VALUE )
		{
			AfxMessageBox(_T("无法打开端口！请检查是否已被占用。"));
			return FALSE;
		}
		GetCommState(m_hComm,&dcb);
		dcb.BaudRate=BaudRate;
		dcb.ByteSize=DataBits;
		dcb.Parity=Parity;
		dcb.StopBits=StopBits;
		dcb.fParity=FALSE;
		dcb.fBinary=TRUE;
		dcb.fDtrControl=0;
		dcb.fRtsControl=0;
		dcb.fOutX=dcb.fInX=dcb.fTXContinueOnXoff=0;
		
		//设置状态参数
		SetCommMask(m_hComm,EV_RXCHAR);		
		SetupComm(m_hComm,16384,16384);		
		if(!SetCommState(m_hComm,&dcb))
		{
			AfxMessageBox(_T("无法按当前参数配置端口，请检查参数！"));
			PurgeComm(m_hComm,PURGE_TXCLEAR|PURGE_RXCLEAR);
			ClosePort();
			return FALSE;
		}
		
		//设置超时参数
		GetCommTimeouts(m_hComm,&CommTimeOuts);		
		CommTimeOuts.ReadIntervalTimeout=100;
		CommTimeOuts.ReadTotalTimeoutMultiplier=1;
		CommTimeOuts.ReadTotalTimeoutConstant=100;
		CommTimeOuts.WriteTotalTimeoutMultiplier=0;
		CommTimeOuts.WriteTotalTimeoutConstant=0;		
		if(!SetCommTimeouts(m_hComm,&CommTimeOuts))
		{
			AfxMessageBox(_T("无法设置超时参数！"));
			PurgeComm(m_hComm,PURGE_TXCLEAR|PURGE_RXCLEAR);
			ClosePort();
			return FALSE;
		}
		
		PurgeComm(m_hComm,PURGE_TXCLEAR|PURGE_RXCLEAR);		
		return TRUE;		
	}
	
	return FALSE;
}

BOOL CPSerialPort::ClosePort()
{
	Deactivate();
	if(m_hComm!=INVALID_HANDLE_VALUE)
	{
		SetCommMask(m_hComm,0);		
		PurgeComm(m_hComm,PURGE_TXCLEAR|PURGE_RXCLEAR);
		CloseHandle(m_hComm);
		m_hComm=INVALID_HANDLE_VALUE;
		return TRUE;
	}
	
	return TRUE;	
}

BOOL CPSerialPort::Activate()
{
	if(m_hComm==INVALID_HANDLE_VALUE)
	{
		return FALSE;
	}

	if(!m_bReceiving)
	{
		//开始接收线程
		PurgeComm(m_hComm,PURGE_TXCLEAR|PURGE_RXCLEAR);
		m_bReceiving=TRUE;
		m_hReadThread=CreateThread(NULL,0,ReadPortThread,this,0,NULL);
	}
	if(m_hReadThread!=NULL)
	{		
		return TRUE;
	}
	else
	{
		m_bReceiving=FALSE;
		return FALSE;
	}

	return FALSE;
}

BOOL CPSerialPort::Deactivate()
{
	if(m_hComm==INVALID_HANDLE_VALUE)
	{
		return FALSE;
	}

	//停止接收线程
	if(m_bReceiving)
	{
		m_bReceiving=FALSE;
		WaitForSingleObject(m_hReadThread,500);
		CloseHandle(m_hReadThread);
		m_hReadThread=NULL;
		return TRUE;
	}

	return FALSE;
}

BOOL CPSerialPort::IsActive()
{
	return m_bReceiving;
}

DWORD CPSerialPort::WritePort(char *data,int length)
{
	if(m_hComm==INVALID_HANDLE_VALUE)
	{
		return 0;
	}

	BOOL fWriteState;
	DWORD dwBytesWritten=0;

	fWriteState=WriteFile(m_hComm,data,length*sizeof(char),&dwBytesWritten,NULL);
	
	return dwBytesWritten;
}

DWORD CPSerialPort::ReadPort(char *data,int length)
{
	BOOL fReadState;
	DWORD dwLength,dwBytesRead;
	int TimeOutCount;

	dwBytesRead=0;
	TimeOutCount=0;
	
	while(m_hComm!=INVALID_HANDLE_VALUE)
	{
		char* buf=new char[length];
		fReadState=ReadFile(m_hComm,data,length,&dwLength,NULL);
		if(!fReadState)
		{
			break;
		}
		else
		{
			dwBytesRead+=dwLength;
			data+=dwLength;			
		}
		if(dwBytesRead==(DWORD)length)
		{
			break;
		}
		if(dwLength!=0)
		{
			TimeOutCount=0;
		}
		else
		{
			TimeOutCount++;
			Sleep(5);
		}
		if(TimeOutCount==5)
		{
			break;
		}
	}
	return dwBytesRead;
}

DWORD CPSerialPort::WriteFileToPort(LPCTSTR FileName)
{
	if(m_hComm==INVALID_HANDLE_VALUE)
	{
		return 0;
	}

	CFile cf;

	BOOL fWriteState;
	DWORD dwBytesWritten;
	DWORD dwCharToWrite;

	dwCharToWrite=0;

	if(!cf.Open(FileName,CFile::modeRead))
	{
		//AfxMessageBox(_T("无法打开Hex文件！"));
		return 0;
	}
	dwCharToWrite=(DWORD)cf.GetLength();
	cf.Seek(0,CFile::begin);
	dwBytesWritten=0;
	
	if(m_hComm!=INVALID_HANDLE_VALUE&&dwCharToWrite!=0)
	{
		char* buf=new char[dwCharToWrite];
		cf.Read(buf,dwCharToWrite);

		fWriteState=WriteFile(m_hComm,buf,dwCharToWrite*sizeof(char),&dwBytesWritten,NULL);
		if(!fWriteState)
		{
			//AfxMessageBox(_T("无法向端口写入数据！"));
		}
		delete[] buf;		
	}
	cf.Close();
	return dwBytesWritten;
}