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  /**//* CommUtils.h */
 #ifndef _CommUtils_H__
#define _CommUtils_H__
class CommUtils
 {
 public:
bool ReadCom(unsigned char * ReceiveData, DWORD& ReceiveLength);
void CloseCom();
bool WriteCom(unsigned char * sendchar,int sendsize);
bool OpenCom(int Port);
CommUtils();
virtual ~CommUtils();
int m_Port;
char szCurPath[256];
private:
OVERLAPPED ReadovReady, WriteovReady;
HANDLE hComm;
bool bOpenCom;
 };
#endif
/**//*
CommUtils.cpp 串口通訊類
Author: edog 2007-11-21
EMail: comwell@126.com
*/
#include "stdafx.h"
#include "CommUtils.h"
#include "stdio.h"
const int READ_TIMEOUT = 500;
CommUtils::CommUtils()
{
bOpenCom = false;
}
CommUtils::~CommUtils()
{
this->CloseCom();
}
bool CommUtils::OpenCom(int Port)
{
if (bOpenCom)
  {
this->CloseCom();
bOpenCom = false;
 }
char szport[10];
sprintf(szport,"COM%d",Port);
hComm = CreateFile( szport,
GENERIC_READ|GENERIC_WRITE,
0,
NULL,
OPEN_EXISTING,
FILE_FLAG_OVERLAPPED, //FILE_ATTRIBUTE_NORMAL|
NULL);
if (hComm == INVALID_HANDLE_VALUE) return false;
if (!SetupComm(hComm, 1024, 512)) return false;
COMMTIMEOUTS commtimeouts;
commtimeouts.ReadIntervalTimeout = MAXDWORD;
commtimeouts.ReadTotalTimeoutConstant =0;
commtimeouts.ReadTotalTimeoutMultiplier =0;
commtimeouts.WriteTotalTimeoutConstant =0;
commtimeouts.WriteTotalTimeoutMultiplier=0;
if (!SetCommTimeouts(hComm, &commtimeouts)) return false;
memset(&ReadovReady,0,sizeof(OVERLAPPED));
memset(&WriteovReady,0,sizeof(OVERLAPPED));
ReadovReady.hEvent = CreateEvent(NULL,TRUE,FALSE,NULL);
WriteovReady.hEvent =CreateEvent(NULL,TRUE,FALSE,NULL);
SECURITY_ATTRIBUTES sa;
sa.nLength=sizeof(SECURITY_ATTRIBUTES);
sa.lpSecurityDescriptor=NULL;
sa.bInheritHandle=TRUE;
DCB dcb;
GetCommState(hComm, &dcb);
dcb.fBinary = TRUE;
dcb.fParity = TRUE;
dcb.BaudRate = CBR_9600; // 波特率 9600
dcb.ByteSize = 8; // 8 位數據位
dcb.Parity = NOPARITY; // 無奇偶校驗
dcb.StopBits = ONESTOPBIT; // 1 個停止位
if (!SetCommState(hComm, &dcb )) return false;
bOpenCom = true;
return bOpenCom;
}
bool CommUtils::WriteCom(unsigned char *sendchar, int sendsize)
{
if (!bOpenCom) return false;
DWORD BytesSent;
DWORD resD;
PurgeComm(hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT);
BytesSent=0;
BOOL hr = WriteFile(hComm, // Handle to COMM Port
sendchar, // Pointer to message buffer in calling finction
sendsize, // Length of message to send
&BytesSent, // Where to store the number of bytes sent
&WriteovReady); // Overlapped structure
if(!hr)
{
if(GetLastError() != ERROR_IO_PENDING)
{
return false;
}
else
{
resD=WaitForSingleObject(WriteovReady.hEvent,INFINITE);
}
switch(resD)
{
case WAIT_OBJECT_0:
{
if(!GetOverlappedResult(hComm,&WriteovReady,&BytesSent,false))
return false;
else
return true;
}
default:
return false;
break;
}
}
return true;
}
void CommUtils::CloseCom()
{
if (!bOpenCom) return;
CloseHandle(hComm);
hComm=NULL;
CloseHandle(ReadovReady.hEvent);
CloseHandle(WriteovReady.hEvent );
ReadovReady.hEvent =NULL;
WriteovReady.hEvent =NULL;
}
bool CommUtils::ReadCom(unsigned char * ReceiveData, DWORD& ReceiveLength)
{
if (!bOpenCom) return false;
if (ReadovReady.hEvent == NULL) return false;
ReceiveLength = 0;
if (ReadFile(hComm, ReceiveData, 128, &ReceiveLength, &ReadovReady) == FALSE)
{
if (GetLastError() != ERROR_IO_PENDING) return false;
}
if(ReceiveLength == 0) return false;
ReceiveData[ReceiveLength] = 0;
DWORD dwRead;
DWORD dwRes = WaitForSingleObject(ReadovReady.hEvent, READ_TIMEOUT);
switch(dwRes)
{
case WAIT_OBJECT_0:
if (!GetOverlappedResult(hComm, &ReadovReady, &dwRead, FALSE)) return false;
break;
case WAIT_TIMEOUT:
break;
default:
break;
}
return true;
}
以下為使用方法：
// 1. 包含頭文件，定義變量
#include "CommUtils.h"
CommUtils theComm;
unsigned char data[1024];
unsigned long len = 0;
// 2. 打開串口，設置接收定時器
theComm.OpenCom(1); // 打開COM1口
SetTimer(1, 50, 0);
// 3. 發送數據
theComm.WriteCom(data, len);
// 4. 接收數據處理
void CUARTDlg::OnTimer(UINT nIDEvent)
{
if (nIDEvent == 1)
{
if (theComm.ReadCom(data, len))
{
if (len > 0)
{
// 接收數據處理。。。
}
}
}
CDialog::OnTimer(nIDEvent);
}
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