串口的读问题

[大头猫]

DWORD WINAPI CommWatchProc1(LPVOID lpParameter)
{
while(m_bCom1Open==true)
{
DWORD dwBytesRead=1024;
DWORD dwEvtMask=0;
OVERLAPPED READ_OS;
//存储读到的数据
char lpInBuffer[1024];
COMSTAT ComStat;
DWORD dwErrorFlags;
//保存串口数据的长度
DWORD dwLength;
SetCommMask( hCom1, EV_RXCHAR|EV_TXEMPTY );//有哪些串口事件需要监视？
WaitCommEvent( hCom1, &dwEvtMask, 0 );// 等待串口通信事件的发生
if ((dwEvtMask & EV_RXCHAR) == EV_RXCHAR)
{
::ClearCommError(hCom1,&dwErrorFlags,&ComStat);
dwLength=ComStat.cbInQue; //输入缓冲区有多少数据？
if (dwLength> 0)
{
BOOL fReadStat;
dwBytesRead=min(dwBytesRead,dwLength);
fReadStat=ReadFile(hCom1,lpInBuffer,dwLength,&dwBytesRead,&READ_OS);
if (!fReadStat)
{
if(GetLastError()==ERROR_IO_PENDING)
{
GetOverlappedResult(hCom1,&READ_OS,&dwBytesRead,TRUE);

}
}

}
}
}

return 0;
}

检测得到写入串口数据的长度，但是没法写进lpInBuffer，希望有人能解

[czydxj]

SetCommMask串口设置不应该放在这里吧

[大头猫]

要吧，不然你怎么知道等待那些消息呢，那个ReadFile 的返回类型是false，我不知道是那种问题

[nalisaki]

使用READ_OS前要memset(&READ_OS,0,sizeof(OVERLAPPED));

[nalisaki]

当读取不成功时，是不是要用一个循环等待一下，直到读取完成呢？

BOOL f;
				f = ReadFile(p->m_hCom,buffer,comState.cbInQue,&data,&over);
				if(!f)
				{
					BOOL m;
					m = GetOverlappedResult(p->m_hCom,&over,&written,true);
					while(!m)
					{
						if(GetLastError() == ERROR_IO_PENDING)
						{
							m = GetOverlappedResult(p->m_hCom,&over,&written,true);
						}
					}
					
				}