我的问题是关于链接 Qt 和 win32 应用程序问题是这样的：我的同事编写了一个使用管道的特殊程序。此管道用于向 GUI 发送特殊消息。GUI 必须在显示屏上显示这些消息。管道程序里面有一个线程。该线程始终在运行并收听内部消息。每当收到消息时，它都会创建一个新线程，并且该线程必须与 GUI 通信并显示消息，然后被杀死（他说必须遵循此例程）。这是他这样使用的代码
DWORD WINAPI PipeThread( void* pContext )
{
BOOL fConnected = FALSE;
DWORD dwThreadId = 0;
HANDLE hPipe = INVALID_HANDLE_VALUE, hThread = NULL;
LPTSTR lpszPipename = TEXT("\\\\.\\pipe\\InterfacePipe");
SECURITY_ATTRIBUTES sa;
sa.lpSecurityDescriptor = (PSECURITY_DESCRIPTOR)malloc(SECURITY_DESCRIPTOR_MIN_LENGTH);
if (!InitializeSecurityDescriptor(sa.lpSecurityDescriptor, SECURITY_DESCRIPTOR_REVISION))
{
DWORD er = ::GetLastError();
}
if (!SetSecurityDescriptorDacl(sa.lpSecurityDescriptor, TRUE, (PACL)0, FALSE))
{
DWORD er = ::GetLastError();
}
sa.nLength = sizeof sa;
sa.bInheritHandle = TRUE;
for (;;)
{
//_tprintf( TEXT("\nPipe Server: Main thread awaiting client connection on %s\n"), lpszPipename);
hPipe = CreateNamedPipe(
lpszPipename, // pipe name
PIPE_ACCESS_DUPLEX, // read/write access
PIPE_TYPE_MESSAGE | // message type pipe
PIPE_READMODE_MESSAGE | // message-read mode
PIPE_WAIT, // blocking mode
PIPE_UNLIMITED_INSTANCES, // max. instances
BUFFER_SIZE, // output buffer size
BUFFER_SIZE, // input buffer size
0, // client time-out
&sa); // default security attribute
if (hPipe == INVALID_HANDLE_VALUE)
{
//_tprintf(TEXT("CreateNamedPipe failed, GLE=%d.\n"), GetLastError());
return -1;
}
// Wait for the client to connect; if it succeeds,
// the function returns a nonzero value. If the function
// returns zero, GetLastError returns ERROR_PIPE_CONNECTED.
fConnected = ConnectNamedPipe(hPipe, NULL) ?
TRUE : (GetLastError() == ERROR_PIPE_CONNECTED);
if (fConnected)
{
// Create a thread for this client.
hThread = CreateThread(
NULL, // no security attribute
0, // default stack size
InstanceThread, // thread proc
(LPVOID) hPipe, // thread parameter
0, // not suspended
&dwThreadId); // returns thread ID
if (hThread == NULL)
{
return -1;
}
else CloseHandle(hThread);
}
else
// The client could not connect, so close the pipe.
CloseHandle(hPipe);
}
return ERROR_SUCCESS;
}
And the code which uses to display message on MFC dialog is this:
DWORD WINAPI InstanceThread(LPVOID lpvParam)
// This routine is a thread processing function to read from and reply to a client
// via the open pipe connection passed from the main loop. Note this allows
// the main loop to continue executing, potentially creating more threads of
// of this procedure to run concurrently, depending on the number of incoming
// client connections.
{
HANDLE hHeap = GetProcessHeap();
TCHAR* pchRequest = (TCHAR*)HeapAlloc(hHeap, 0, BUFFER_SIZE*sizeof(TCHAR));
TCHAR* pchReply = (TCHAR*)HeapAlloc(hHeap, 0, BUFFER_SIZE*sizeof(TCHAR));
DWORD cbBytesRead = 0, cbReplyBytes = 0, cbWritten = 0;
BOOL fSuccess = FALSE;
HANDLE hPipe = NULL;
// Do some extra error checking since the app will keep running even if this
// thread fails.z
if (lpvParam == NULL)
{
if (pchReply != NULL) HeapFree(hHeap, 0, pchReply);
if (pchRequest != NULL) HeapFree(hHeap, 0, pchRequest);
return (DWORD)-1;
}
if (pchRequest == NULL)
{
if (pchReply != NULL) HeapFree(hHeap, 0, pchReply);
return (DWORD)-1;
}
if (pchReply == NULL)
{
if (pchRequest != NULL) HeapFree(hHeap, 0, pchRequest);
return (DWORD)-1;
}
// Print verbose messages. In production code, this should be for debugging only.
// The thread's parameter is a handle to a pipe object instance.
hPipe = (HANDLE) lpvParam;
// Loop until done reading
while (1)
{
// Read client requests from the pipe. This simplistic code only allows messages
// up to BUFSIZE characters in length.
fSuccess = ReadFile(
hPipe, // handle to pipe
pchRequest, // buffer to receive data
BUFFER_SIZE*sizeof(TCHAR), // size of buffer
&cbBytesRead, // number of bytes read
NULL); // not overlapped I/O
if (!fSuccess || cbBytesRead == 0)
{
break;
}
MyData* data = new MyData;
data->client_Param = pchRequest;
HWND handle = FindWindow(NULL,CStringW("MFCApplication1"));
PostMessage(handle, WM_YOU_HANVE_DATA, reinterpret_cast<WPARAM>(data) ,NULL);
// Process the incoming message.
//GetAnswerToRequest(pchRequest, pchReply, &cbReplyBytes);
if (wcscmp(pchRequest,L"msg1")==0)
StringCchCopy( pchReply, BUFFER_SIZE, TEXT("Hi"));
else
StringCchCopy( pchReply, BUFFER_SIZE, TEXT("default echo answer"));
cbReplyBytes = (lstrlen(pchReply)+1)*sizeof(TCHAR);
// Write the reply to the pipe.
fSuccess = WriteFile(
hPipe, // handle to pipe
pchReply, // buffer to write from
cbReplyBytes, // number of bytes to write
&cbWritten, // number of bytes written
NULL); // not overlapped I/O
if (!fSuccess || cbReplyBytes != cbWritten)
{
break;
}
}
// Flush the pipe to allow the client to read the pipe's contents
// before disconnecting. Then disconnect the pipe, and close the
// handle to this pipe instance.
FlushFileBuffers(hPipe);
DisconnectNamedPipe(hPipe);
CloseHandle(hPipe);
HeapFree(hHeap, 0, pchRequest);
HeapFree(hHeap, 0, pchReply);
return 1;
}
如您所见，他使用函数而不是方法。我创建了一个类并推送他的方法并使用信号和插槽来实现目标。但它会崩溃。原因是 createThread 方法必须获取函数名而不是方法名。因此，我将该方法创建为静态方法，但又引发了另一个错误。信号和槽应该使用一个真实的对象（在 moc 文件中它使用与此方法不兼容的“this”关键字）我应该如何克服这个问题
PipeCreator::PipeCreator(QObject *parent = 0) :
QObject(parent)
{
HANDLE hPipeThread = CreateThread( NULL, 0, PipeCreator::PipeThread, NULL, 0, NULL );
}
DWORD PipeCreator::PipeThread(void *pContext)
{
BOOL fConnected = FALSE;
DWORD dwThreadId = 0;
HANDLE hPipe = INVALID_HANDLE_VALUE, hThread = NULL;
LPTSTR lpszPipename = TEXT("\\\\.\\pipe\\InterfacePipe");
// The main loop creates an instance of the named pipe and
// then waits for a client to connect to it. When the client
// connects, a thread is created to handle communications
// with that client, and this loop is free to wait for the
// next client connect request. It is an infinite loop.
SECURITY_ATTRIBUTES sa;
sa.lpSecurityDescriptor = (PSECURITY_DESCRIPTOR)malloc(SECURITY_DESCRIPTOR_MIN_LENGTH);
if (!InitializeSecurityDescriptor(sa.lpSecurityDescriptor, SECURITY_DESCRIPTOR_REVISION))
{
DWORD er = ::GetLastError();
}
if (!SetSecurityDescriptorDacl(sa.lpSecurityDescriptor, TRUE, (PACL)0, FALSE))
{
DWORD er = ::GetLastError();
}
sa.nLength = sizeof sa;
sa.bInheritHandle = TRUE;
for (;;)
{
hPipe = CreateNamedPipe(
lpszPipename, // pipe name
PIPE_ACCESS_DUPLEX, // read/write access
PIPE_TYPE_MESSAGE | // message type pipe
PIPE_READMODE_MESSAGE | // message-read mode
PIPE_WAIT, // blocking mode
PIPE_UNLIMITED_INSTANCES, // max. instances
BUFFER_SIZE, // output buffer size
BUFFER_SIZE, // input buffer size
0, // client time-out
&sa); // default security attribute
if (hPipe == INVALID_HANDLE_VALUE)
{
return -1;
}
// Wait for the client to connect; if it succeeds,
// the function returns a nonzero value. If the function
// returns zero, GetLastError returns ERROR_PIPE_CONNECTED.
fConnected = ConnectNamedPipe(hPipe, NULL) ?
TRUE : (GetLastError() == ERROR_PIPE_CONNECTED);
if (fConnected)
{
this->instance =new InstanceCreator();
connect(this->instance,SIGNAL(NewDataAvailable(MyData)),this,SLOT(NewDataAvailableForGUI(MyData)));
// Create a thread for this client.
hThread = CreateThread(
NULL, // no security attribute
0, // default stack size
this->instance->InstanceThread, // thread proc
(LPVOID) hPipe, // thread parameter
0, // not suspended
&dwThreadId); // returns thread ID
if (hThread == NULL)
{
return -1;
}
else
{
//Here I should recieve the emmited signal
emit NewDataAvailableForGUI(this->newData);
CloseHandle(hThread);
}
}
else
// The client could not connect, so close the pipe.
CloseHandle(hPipe);
}
return ERROR_SUCCESS;
}
// This routine is a thread processing function to read from and reply to a client
// via the open pipe connection passed from the main loop. Note this allows
// the main loop to continue executing, potentially creating more threads of
// of this procedure to run concurrently, depending on the number of incoming
// client connections.
DWORD InstanceCreator::InstanceThread(LPVOID lpvParam)
{
HANDLE hHeap = GetProcessHeap();
TCHAR* pchRequest = (TCHAR*)HeapAlloc(hHeap, 0, BUFFER_SIZE*sizeof(TCHAR));
TCHAR* pchReply = (TCHAR*)HeapAlloc(hHeap, 0, BUFFER_SIZE*sizeof(TCHAR));
DWORD cbBytesRead = 0, cbReplyBytes = 0, cbWritten = 0;
BOOL fSuccess = FALSE;
HANDLE hPipe = NULL;
// Do some extra error checking since the app will keep running even if this
// thread fails.z
//PostMessage((HWND)CMFCApplication1Dlg->textBox3->Handle.ToPointer(), WM_SETTEXT, 0, (LPARAM)L"TestDLL Try");
if (lpvParam == NULL)
{
if (pchReply != NULL) HeapFree(hHeap, 0, pchReply);
if (pchRequest != NULL) HeapFree(hHeap, 0, pchRequest);
return (DWORD)-1;
}
if (pchRequest == NULL)
{
if (pchReply != NULL) HeapFree(hHeap, 0, pchReply);
return (DWORD)-1;
}
if (pchReply == NULL)
{
if (pchRequest != NULL) HeapFree(hHeap, 0, pchRequest);
return (DWORD)-1;
}
// Print verbose messages. In production code, this should be for debugging only.
// The thread's parameter is a handle to a pipe object instance.
hPipe = (HANDLE) lpvParam;
// Loop until done reading
while (1)
{
// Read client requests from the pipe. This simplistic code only allows messages
// up to BUFSIZE characters in length.
fSuccess = ReadFile(
hPipe, // handle to pipe
pchRequest, // buffer to receive data
BUFFER_SIZE*sizeof(TCHAR), // size of buffer
&cbBytesRead, // number of bytes read
NULL); // not overlapped I/O
if (!fSuccess || cbBytesRead == 0)
{
break;
}
MyData data;
data.data=QString::fromStdWString(pchRequest);
emit NewDataAvailable(data);
// Process the incoming message.
//GetAnswerToRequest(pchRequest, pchReply, &cbReplyBytes);
if (wcscmp(pchRequest,L"msg1")==0)
StringCchCopy( pchReply, BUFFER_SIZE, TEXT("Hi"));
else
StringCchCopy( pchReply, BUFFER_SIZE, TEXT("default echo answer"));
cbReplyBytes = (lstrlen(pchReply)+1)*sizeof(TCHAR);
// Write the reply to the pipe.
fSuccess = WriteFile(
hPipe, // handle to pipe
pchReply, // buffer to write from
cbReplyBytes, // number of bytes to write
&cbWritten, // number of bytes written
NULL); // not overlapped I/O
if (!fSuccess || cbReplyBytes != cbWritten)
{
break;
}
}
// Flush the pipe to allow the client to read the pipe's contents
// before disconnecting. Then disconnect the pipe, and close the
// handle to this pipe instance.
FlushFileBuffers(hPipe);
DisconnectNamedPipe(hPipe);
CloseHandle(hPipe);
HeapFree(hHeap, 0, pchRequest);
HeapFree(hHeap, 0, pchReply);
return 1;
}