asked on

BN_CLICKED and the message queue

I'm trying to perfom an operation if a certain button is clicked within a Dialog created with the CDialog constructor and Create. After creating the dialog, I'm going into a loop which processes messages using PeekMessage. The problem is, the WM_COMMAND and BN_CLICKED messages never show themselves with PeekMessage. Can someone please tell me what I am doing incorrectly:

CDialog *dlgProductKey = new CDialog();
MSG msg;

dlgProductKey->Create(IDD_ENTERKEY, this);
dlgProductKey->ShowWindow(SW_SHOW);

while (dlgProductKey->IsWindowVisible()) {

if (PeekMessage(&msg, dlgProductKey->m_hWnd, 0, 0, PM_REMOVE)) {

      if (msg.message == WM_COMMAND && HIWORD(msg.wParam) == BN_CLICKED){
           MessageBox("Button was clicked");
      }

      TranslateMessage(&msg);
      DispatchMessage(&msg);
}
}

When I use the Microsoft Message Spy, I can clearly see that the dlgProductKey dialog is receiving the WM_COMMAND|BN_CLICKED message. Do I have to subclass the dialog, or is there an easier way (like the method I am attempting). I was hoping not to create a new class for the IDD_ENTERKEY dialog resource.

nonubik

The simplest way is to add an event handler to your button.
Go to your dialog resource, right click on the desired button and choose 'Events..' Then select BN_CLICKED and choose 'Add and edit'. You will be asked for the handler method name.

Skonen

ASKER

That only works if the dialog resource has an associated class, I can do that quicker than you can blink. But now it isn't so much over how to do it the fastest, I am just wondering what I'd have to do to make the code above work properly.

OnegaZhang

I think you need to call IsDialogMessage in the message loop.

welcome to www.fruitfruit.com

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nonubik

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MikeAThon

I think OnegaZhang is correct: you need to call IsDialogMessage.

But since this is an MFC app, you might get better results by calling CWinThread::PumpMessage:

while (dlgProductKey->IsWindowVisible()) {

if (PeekMessage(&msg, dlgProductKey->m_hWnd, 0, 0, PM_NOREMOVE)) { // <<-- note change to PM_NOREMOVE

if (msg.message == WM_COMMAND && HIWORD(msg.wParam) == BN_CLICKED){
MessageBox("Button was clicked");
}

AfxGetApp()->PumpMessage();

}
}