Message windows question

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Hi I have a question regarding message windows. I have a class (CWnd based), in which I create a message only window. Then I add the

C#

BEGIN_MESSAGE_MAP(MyClass, CWnd)
    //{{AFX_MSG_MAP(MyClass)
    ON_REGISTERED_MESSAGE(WM_MyClass_MSG_TO_THREAD,OnMyClassMsg2)
    //}}AFX_MSG_MAP
END_MESSAGE_MAP()

then in a working thread I create a that class
MyClass *class = new MyClass;
Now in the UI thread I find the window
::FindWindow(...);
and then post a message to it
::PostMessage(...);
I use user registered messages, I do find the window, but the message is never captured by the window, so I don't get anything in the OnMyClassMsg2 function.
Is there anything wrong I'm doing?

Posted 1-Aug-11 6:03am

xumepoc

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4 solutions

Solution 1

After you allocate the class you need to call create() on it:

MyClass *class =  new MyClass;
MyClass->create();

See: http://msdn.microsoft.com/en-us/library/0yhc9kx4(v=VS.90).aspx[^]

Posted 1-Aug-11 6:19am

TRK3

Solution 2

I was creating the window in the class itself

C++

void MyClass::MyClass(void){
        CString wnd_class_name = ::AfxRegisterWndClass(NULL);
	this->CreateEx(0,wnd_class_name, "TEST_THREAD_WINDOW",0 ,0 ,0 ,0 ,0 ,HWND_MESSAGE,0);
	TRACE("WINDOW READY\n");
}

I did what you suggested and the result was the same, as I said, I can find the window, the FindWindowEx(..) returns HWND, so the window is there, but the message is simply not captured by it. I have double checked the registers message and so on and everything is ok, but no result in the function for the received message.

Edit: I mean FindWindowEx, not FindWindow of course.

Posted 1-Aug-11 6:28am

xumepoc

Updated 1-Aug-11 6:42am

v2

Comments

TRK3 1-Aug-11 14:04pm

If you add a comment to my solution then I'll get an email letting me know you commented. Adding a new solution doesn't notify me.

(Also, since it isn't a solution, but a further explanation of the question, it shouldn't be a solution. Either edit your original question to add the additional data, or comment on the proposed solution.)

That said. See my additional solution below.

Solution 4

Thanks, that did the trick, I didn't know that the working thread doesn't have a message loop. Thanks, Solved!!

Posted 1-Aug-11 8:25am

xumepoc

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TRK3 · Accepted Answer · 2011-08-01T08:09:00

OK, so you alocated and created a window in a worker thread.

So the next question, is what is the worker thread doing? (Did it already finish, or is it busy doing some other work?)

A worker thread doesn't natively have a message loop, so unless you are explicitly getting messages and dispatching them somewhere in your worker thread, then you'll never see the message.

Typically you'd do something like:

while ( im_not_doing_anything_else ) 
{
    MSG m;
    GetMessage(&m,0,0,0);
    TranslateMessage(&m);
    DispatchMessage(&m);
}

Message windows question

4 solutions

Solution 3

Solution 1

Solution 2

Solution 4

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