用ReadFile读串口时出现ERROR_IO_PENDING错误,不知如何解决.

[Andy84920]

我看了MSDN.处理是:

case ERROR_IO_PENDING:
{
// asynchronous i/o is still in progress

// do something else for a while
GoDoSomethingElse() ;

// check on the results of the asynchronous read
bResult = GetOverlappedResult(hFile, &gOverlapped,
&nBytesRead, FALSE) ;

// if there was a problem ...
if (!bResult)
{
// deal with the error code
switch (dwError = GetLastError())
{
case ERROR_HANDLE_EOF:
{
// we're reached the end of the file
//during asynchronous operation
}

// deal with other error cases
}
}
} // end case

好像是等待的时间很短就去读串口了,但我已经等待了2妙还是不行.要怎么样处理这个问题呢?

[Andy84920]

而我用的处理办法是:

if( dwErrCode == ERROR_IO_PENDING )
{
while( !GetOverlappedResult(m_hCom,&m_ros,&dwRead,FALSE ) )
{
dwErrCode = GetLastError();
if( dwErrCode == ERROR_IO_INCOMPLETE )
{
if ((GetTickCount()-dwTime) > nTimeOut)
{
ClearCommError( m_hCom, &dwErrorFlags, &ComStat );
return QE_FAIL;
}
Sleep(1000) ;
continue;
}
else
{
ClearCommError( m_hCom, &dwErrorFlags, &ComStat ) ;
if ( dwErrorFlags > 0)
{
//g_pEventLog->ErrorEventParamLog("Read COM Error: %u,<CE-%u>",dwErrCode,dwErrorFlags ) ;
}
break ;
}
}
}

而用GetOverlappedResult返回的结果是true.那会是哪里的问题呢?