How do you disable CBitmapButton?

Question

How do you disable CBitmapButton? I tried using m_bitmapbutton.EnableWindow(false); but it doesn't work. It still fires an event.

What I'm trying to do is prevent Button A from firing Event A if Event B is executing (from Button B). So in Event B, I want to disable Button A.

Answer 1

Here's a list of things to check:

• Did you define an image for the bitmap button's disabled state?
• Are you sure the event is fired?
• Event B isn't in a thread is it?
• Are you doing an m_bitmapbutton.EnableWindow(FALSE) at the start of Event B and m_bitmapbutton.EnableWindow(TRUE) at the end?
• Are you doing a BN_CLICKED Notification ()? Or is it maybe a different notification such as WM_LBUTTONDOWN Notification ()?
• Are you sure that the variable m_bitmapbutton is properly associated with your button A? Could you try with GetDlgItem(IDC_BUTTON_A)->EnableWindow(FALSE);

You could always just set a boolean member variable to indicate that Button A is disabled, and ignore any events sent to it when this boolean member is set.

It may be easier to use this class from CodeProject.

Answer 2

Hi Sal,

I suppose the problem is that while you are attending the Event B, the messages for this window are not being dispatched. So they are being queued and dispathched after you finish to attend the Event B and you have enabled the button A again. Something like that:

1. OnBnClickedButtonB
2. buttonA.EnableWindow(FALSE) (mouse events for the window are being queued and not dispatched)
3. buttonA.EnableWindow(TRUE)
4. ~OnBnClickedButtonB (the application dispatch queued events so the button is enabled again)

This is not just a problem with a CBitmapButton...it should happed with any other button (I haven't tried myself).

A possible workaround could be dispatching mouse events for this window before enabling the button again...although I didn't like too much do this kind of thigs...maybe someone can give you a better solution:

void CMyDlg::OnBnClickedButtonB()
{
    m_buttonA.EnableWindow(FALSE);

    //Process button B clicked event 

    MSG msg;
    while(PeekMessage( &msg, 
       GetSafeHwnd(), 
       WM_MOUSEFIRST, 
       WM_MOUSELAST, 
       PM_REMOVE))
    {
     TranslateMessage(&msg);
     DispatchMessage(&msg);  
    }

    m_buttonA.EnableWindow(TRUE);
}

Hope this help!

Javier