d193.bmp.txt

Visual C++通信编程实例

do
{
TRACE(_TEXr("m_hFileHandle error_W.\n"》;
retuni -1;
int nRet;
DWORD dwLastError;
DWORD dwHaveWntten = 0;
DWORD dwStartWrite = 0; 11在起始处开始
 DWORD dwNumToWrite = dwCount;
DWORD dwHandleSignaled;
 HANDLE HandlesToWaitFor[2] ;
 int iWait=2;
HandlesToWaitFor[OJ = m_overlappedWrite.hEvent;
HandlesToWaitFor[l] = m_hStopWriteEvent;
，，不停循环直到所有字符都写完
// Start the overlapped I/O.
if ( !WriteFile《HANDLE)m_hFileHandle,
                 (LPCVOID)&(lpszS tringToWrite[dwStartWritel),
(DWORD)dwCount,
(LPDWORD)&dwHaveWritten,
(LPOVERLAPPED)&m_overlappedWrite》
{
       //WriteFile failed.   Expected;lets handleit.
       dwLastError = GetLastError();
//Its possible for this error to occur if the
// service provider has closed the port.    Time to end.
 if(GetLastError() != ERROR_IO_PENDING)
 {
        IRACE(_TEXT("Error to writing to CommFile%x\n"),dwLastError);
nRet=-l;
       goto Exit;
 }
//Wait for either overlapped I/O completion, or for the CloseEvent to get signaled.
dwHandleSignaled =
         WaitForMultipleObjects(2, HandlesToWaitFor,
FALSE,5000);
switch(dwHandleSignaled)
    {
case WAIT_OBJECT_O : // Wait firushed.
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