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分享PostThreadmessage为什么不能向CWinThread对象发消息怎么回事
我已经建立了一个CWinThread对象，用ON_THREAD_MESSAGE定义
消息映射。也知道了它的线程ID，但为什么用windows的
PostTreadMessage根据线程ID发消息时，这个对象没有反应。
解决的办法是什么呢，请各位高手指点迷津。
消息映射。也知道了它的线程ID，但为什么用windows的
PostTreadMessage根据线程ID发消息时，这个对象没有反应。
解决的办法是什么呢，请各位高手指点迷津。
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penter 2003-07-17
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RESOLUTION
The following code demonstrates how to call PostThreadMessage() in the InitInstance() of the CWinApp-derived class using a single-threaded application. The principle is the same for secondary threads except that the code shown here would be put in your alternate CWinThread-derived class.
Visual C++ 4.2 does support handling messages posted to threads. For more information, see ON_THREAD_MESSAGE in the Visual C++ 4.2 documentation.
NOTE: MFC worker threads do not have a message loop/pump associated with them so you must use a user-interface thread.
Sample Code
/* Compile options needed:
standard MFC project generated by AppWizard */
BOOL CThreadMsgApp::PreTranslateMessage(MSG* pMsg)
{
// Is it the Message you want?
// You can use a switch statement but because this is
// only looking for one message, you can use the if/else
if (pMsg->message == WM_USER+2268)
{
// Call the function to handle this message
OnReceivedCommand(pMsg->wParam,pMsg->lParam);
// Tell MFC no more processing is needed
return TRUE;
}
else
// Call MFC to have it continue processing the message
return CWinThread::PreTranslateMessage(pMsg);
}
BOOL CThreadMsgApp::InitInstance()
{
WPARAM wParam;
LPARAM lParam;
wParam = MAKEWPARAM(0,0); // We can put whatever we
lParam = MAKELPARAM(0,0); // want in wParam & lParam
// Send the user-defined Thread Message
// m_nThreadID is a member of CWinThread that holds the thread ID
PostThreadMessage(m_nThreadID, WM_USER+2268, wParam, lParam);
return TRUE;
}
void CThreadMsgApp::OnReceivedCommand(WPARAM wParam, LPARAM lParam)
{
// You can do whatever you want in here, this is simply
// sending output to the debug window
TRACE0("Received WM_USER+2268!!\n");
}
初学，不知道，请指教；
The following code demonstrates how to call PostThreadMessage() in the InitInstance() of the CWinApp-derived class using a single-threaded application. The principle is the same for secondary threads except that the code shown here would be put in your alternate CWinThread-derived class.
Visual C++ 4.2 does support handling messages posted to threads. For more information, see ON_THREAD_MESSAGE in the Visual C++ 4.2 documentation.
NOTE: MFC worker threads do not have a message loop/pump associated with them so you must use a user-interface thread.
Sample Code
/* Compile options needed:
standard MFC project generated by AppWizard */
BOOL CThreadMsgApp::PreTranslateMessage(MSG* pMsg)
{
// Is it the Message you want?
// You can use a switch statement but because this is
// only looking for one message, you can use the if/else
if (pMsg->message == WM_USER+2268)
{
// Call the function to handle this message
OnReceivedCommand(pMsg->wParam,pMsg->lParam);
// Tell MFC no more processing is needed
return TRUE;
}
else
// Call MFC to have it continue processing the message
return CWinThread::PreTranslateMessage(pMsg);
}
BOOL CThreadMsgApp::InitInstance()
{
WPARAM wParam;
LPARAM lParam;
wParam = MAKEWPARAM(0,0); // We can put whatever we
lParam = MAKELPARAM(0,0); // want in wParam & lParam
// Send the user-defined Thread Message
// m_nThreadID is a member of CWinThread that holds the thread ID
PostThreadMessage(m_nThreadID, WM_USER+2268, wParam, lParam);
return TRUE;
}
void CThreadMsgApp::OnReceivedCommand(WPARAM wParam, LPARAM lParam)
{
// You can do whatever you want in here, this is simply
// sending output to the debug window
TRACE0("Received WM_USER+2268!!\n");
}
初学，不知道，请指教；
penter 2003-07-17
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当一个线程第一次被建立时，系统假定线程不会陪被用于任何与用户相关的任务。以此来减少线程对系统资源的要求。但当线程调用与用户界面相关的函数的时候（例如检查它的消息队列或建立一个窗口），系统就会为该线程分配其他资源，其中就有THREADINFO结构，它是窗口消息的基础；
但CWinThread有用户界面相关的东东吗？也就是，它是否有自己的窗口吗？
When you call PostThreadMessage(), the message is placed in the thread's message queue. However, because messages posted this way are not associated with a window, MFC will not dispatch them to message or command handlers. In order to handle these messages, override the PreTranslateMessage() function of your CWinApp-derived class, and handle the messages manually.
看来没有；MFC不转发与窗口无关的线程消息；
但CWinThread有用户界面相关的东东吗？也就是，它是否有自己的窗口吗？
When you call PostThreadMessage(), the message is placed in the thread's message queue. However, because messages posted this way are not associated with a window, MFC will not dispatch them to message or command handlers. In order to handle these messages, override the PreTranslateMessage() function of your CWinApp-derived class, and handle the messages manually.
看来没有；MFC不转发与窗口无关的线程消息；
zhangjustice 2003-07-12
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大哥们，我已经重载了PreTranslateMessage 函数，但还是不行，不仅重载了CWinThread的
而且重载了App的，也不行，发送成功的消息不知道到哪去了，这到底是怎么回事？
而且重载了App的，也不行，发送成功的消息不知道到哪去了，这到底是怎么回事？
zhangjustice 2003-07-12
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请问问PreTranslateMessage的怎样重载呀？
penter 2003-07-02
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mark
;
;
yongdu 2003-07-02
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你如果发送成功，确信是没收到消息的话，你有可能要在你的线程类内重载PreTranslateMessage() ， 如果你没有关联窗口的话。
littlebiy 2003-06-29
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如果接收消息处理的函数执行时间太长，而同一消息又特别多的话，很容易造成消息的阻塞。
因此如果是消息函数执行时间太长的，一般不必考虑消息的形式，可以考虑在发消息前将发送的数据存储到一个链表中，然后建立一个线程，在线程中再慢慢的处理这些链表中的数据。
另外，也可以在接收消息的函数中，立即处理消息，免得引发一步的阻塞。
因此如果是消息函数执行时间太长的，一般不必考虑消息的形式，可以考虑在发消息前将发送的数据存储到一个链表中，然后建立一个线程，在线程中再慢慢的处理这些链表中的数据。
另外，也可以在接收消息的函数中，立即处理消息，免得引发一步的阻塞。
ahao 2003-06-29
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另一个帖子里回答你了
JetLuo 2003-06-29
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自己写消息循环：
int CMyThread::Run()
{
MSG msg;
while(1)
{
MsgWaitForMultipleObjects( 0,
NULL,
FALSE,
INFINITE,
QS_ALLINPUT );
while(::PeekMessage(&msg, NULL, 0, 0, PM_REMOVE) )
{
switch( msg.message )
{
case WM_MESS:
DoSomething()
break;
default:
break;
}
}
}
return CWinThread::Run();
}
int CMyThread::Run()
{
MSG msg;
while(1)
{
MsgWaitForMultipleObjects( 0,
NULL,
FALSE,
INFINITE,
QS_ALLINPUT );
while(::PeekMessage(&msg, NULL, 0, 0, PM_REMOVE) )
{
switch( msg.message )
{
case WM_MESS:
DoSomething()
break;
default:
break;
}
}
}
return CWinThread::Run();
}
zhangjustice 2003-06-29
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楼上的哥们的建议我试了，不过用PostThreadMessage通过线程发的消息还是接收不到
这是怎么回事？
这是怎么回事？
zhangjustice 2003-06-27
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用CWinThread类中的PostThreadMessage就能收到，msdn是这样写的
The posted message is mapped to the proper message handler by the message map macro ON_THREAD_MESSAGE.
Note When calling the Windows PostThreadMessage function within an MFC application, the MFC message handlers are not called. For more information, see the Knowledge Base article, "PRB: MFC Message Handler Not Called with PostThreadMessage()" (Q142415).
这到底是怎么回事，请各位高手指点，如果我要是重载run函数得怎么办？
The posted message is mapped to the proper message handler by the message map macro ON_THREAD_MESSAGE.
Note When calling the Windows PostThreadMessage function within an MFC application, the MFC message handlers are not called. For more information, see the Knowledge Base article, "PRB: MFC Message Handler Not Called with PostThreadMessage()" (Q142415).
这到底是怎么回事，请各位高手指点，如果我要是重载run函数得怎么办？
yongdu 2003-06-27
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应该用while(!PostThreadMessage(...)) Sleep(10)
可能用一次PostThreadMessage不成功.
可能用一次PostThreadMessage不成功.
ahalf 2003-06-27
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没有消息队列
