vc writefile 997错误 串口通信 20分求解答 昨晚熬到12点都没整出来
所有代码如下 麻烦大神给看看 辛苦了
// Rs232Com.cpp: implementation of the CRs232Com class.
//
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "ComDataAgent.h"
#include "Rs232Com.h"

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

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

CRs232Com::CRs232Com()
: m_iTID(0)
{
hCom = 0;
hThread = 0;
IsOpen = false;
m_pParent = NULL;
}

CRs232Com::~CRs232Com()
{

}

int CRs232Com::Open(CString strPortName)
{
hCom = CreateFile( strPortName,
GENERIC_READ | GENERIC_WRITE,
0, // must be opened with exclusive-access
NULL, // no security attributes
OPEN_EXISTING, // must use OPEN_EXISTING
FILE_FLAG_OVERLAPPED, // not overlapped I/O
NULL // hTemplate must be NULL for comm devices
);

if (hCom == INVALID_HANDLE_VALUE)
{
// Handle the error.
//TRACE ("CreateFile failed with error %d.\n", GetLastError());
return 1;
}

COMMTIMEOUTS cs;
::GetCommTimeouts(hCom,&cs);
cs.ReadIntervalTimeout = 100;
cs.ReadTotalTimeoutConstant = 100;
cs.ReadTotalTimeoutMultiplier = 10;
cs.WriteTotalTimeoutConstant = 100;
cs.WriteTotalTimeoutMultiplier = 10;
::SetCommTimeouts(hCom,&cs);


IsOpen = true;
return 0;
}

BOOL CRs232Com::GetCommState()
{
return ::GetCommState(hCom, &dcb);
}

BOOL CRs232Com::SetCommState(DWORD Baud, DWORD ByteSize, DWORD Parity, DWORD StopBits)
{


dcb.BaudRate = Baud; // set the baud rate
dcb.ByteSize = (BYTE)ByteSize; // data size, xmit, and rcv
dcb.Parity = (BYTE)Parity; // no parity bit
dcb.StopBits = (BYTE)StopBits; // one stop bit
dcb.EvtChar = 13;


return ::SetCommState(hCom, &dcb);

}


void CRs232Com::Close()
{
IsOpen = false;
if(hThread)
{
::WaitForSingleObject(hThread,1000*5);
CloseHandle(hThread);
}
if(hCom)
CloseHandle(hCom);
hCom = 0;
hThread = 0;
}

#define MAX_RECV_BUFFER 8 * 1024
DWORD CRs232Com::ThreadProc(LPVOID lParam)
{
CRs232Com * pCom = (CRs232Com *)lParam;


CString strTID;
strTID.Format(_T("%d"),pCom->m_iTID);

TRACE(strTID);
TRACE(_T("线程启动\n"));

//20110825
int nBufferLen = 0;
char Buffer[MAX_RECV_BUFFER + 1];

memset(Buffer,0,MAX_RECV_BUFFER + 1);

OVERLAPPED o;
o.hEvent = CreateEvent(
NULL, // default security attributes
TRUE, // auto reset event
FALSE, // not signaled
NULL // no name
);
o.Internal = 0;
o.InternalHigh = 0;
o.Offset = 0;
o.OffsetHigh = 0;


// Clear comm buffers at startup
PurgeComm(pCom->hCom, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT);


DWORD dwr;
BOOL IsRead = false;
DWORD dwEvtMask = 0;
while(pCom->IsOpen)
{
ResetEvent(o.hEvent);
WaitCommEvent(pCom->hCom,&dwEvtMask,&o);

if(pCom->m_iTID == 100 && 0)
{
int ii = 0;
}
if (dwEvtMask & EV_RXCHAR)
{

DWORD dwError;
COMSTAT comstat;

if(!pCom->IsOpen)

{
break;
}
BOOL bResult = ClearCommError(pCom->hCom, &dwError, &comstat);

if (comstat.cbInQue == 0)
{
Sleep(10);
continue;
}
if(dwError != 0)
{
int i = 0;
}

OVERLAPPED o1;
o1.hEvent = CreateEvent(
NULL, // default security attributes
FALSE, // auto reset event
FALSE, // not signaled
NULL // no name
);
o1.Internal = 0;
o1.InternalHigh = 0;
o1.Offset = 0;
o1.OffsetHigh = 0;


unsigned int nRemainLen = MAX_RECV_BUFFER - nBufferLen;
if(comstat.cbInQue > nRemainLen)
{
//comstat.cbInQue = 1024;
comstat.cbInQue = MAX_RECV_BUFFER - nBufferLen;
}

//comstat.cbInQue = 100;
if(!pCom->IsOpen)
{
break;
}
//int ll = ReadFile(pCom->hCom,Buffer,comstat.cbInQue,&dwr,&o1);
int ll = ReadFile(pCom->hCom,Buffer + nBufferLen,comstat.cbInQue,&dwr,&o1);
//TRACE("20110825-----%d,%d\n",dwr,nBufferLen);

int nFnd = nBufferLen;
nBufferLen += dwr;
for(;nFnd < nBufferLen;nFnd++)
{
if (Buffer[nFnd] == '\n' || Buffer[nFnd] == '\r')
{
char *tmpBuffer = new char[nFnd + 2];
if (tmpBuffer)
{
memcpy(tmpBuffer,Buffer,nFnd + 1);
memmove(Buffer,&Buffer[nFnd + 1],nFnd + 1);
nBufferLen -= (nFnd + 1);

tmpBuffer[nFnd + 1] = '\0';

if((pCom->IsOpen) && (pCom->m_pParent))
pCom->m_pParent->SendMessage(WM_COMM_RXCHAR,(WPARAM)tmpBuffer,nFnd + 1);

nFnd = 0;
}

//break;
}
}


}

ResetEvent(o.hEvent);
o.Internal = 0;
o.InternalHigh = 0;
o.Offset = 0;
o.OffsetHigh = 0;
dwEvtMask = 0;
IsRead = false;
Sleep(10);
}

TRACE(strTID);
TRACE(_T("线程结束\n"));
//theApp.m_pMainWnd->PostMessageW(WM_COMM_THREAD_END,0,0);
return 0;
}

BOOL CRs232Com::SetCommMask(DWORD dwEvtMask)
{

::SetCommMask(hCom,dwEvtMask);

hThread = CreateThread(
NULL, // default security attributes
0, // use default stack size
ThreadProc, // thread function
this, // argument to thread function
0, // use default creation flags
&dwThreadID); // returns the thread identifier

return 0;
}

int CRs232Com::Send(char * pBuff, long lLen)
{
if(IsOpen == false)
{
return -1;
}

UCHAR sdata[1024];
memset(sdata,0,1024);
memcpy(sdata,pBuff,lLen);

DWORD num = 0;
OVERLAPPED o;
o.hEvent = CreateEvent(
NULL, // default security attributes
FALSE, // auto reset event
FALSE, // not signaled
NULL // no name
);
o.Internal = 0;
o.InternalHigh = 0;
o.Offset = 0;
o.OffsetHigh = 0;

//int re = WriteFile(hCom,Buffer,Len,&num,&o);
int re = WriteFile(hCom,sdata,lLen,&num,&o);
return num;
}


[解决办法]
// 错误997描述如下
ERROR_IO_PENDING
997 (0x3E5)
Overlapped I/O operation is in progress.

// 串口异步操作，返回这个表示操作还未完成，应该继续等待，直至event到达（错误或者完成）