Question

Imagine I have a CDialog which creates controls dynamically when the user clicks a button. It could be like this:

// We don't know which is the first id for the new buttons until runtime (!)
MyDialog::MyDialog(/*whatever parameters needed*/, first_id)
  : next_id_(first_id) 
{ /*...*/ }

BOOL MyDialog::OnSomeButtonClicked()
{
  CButton* new_button = new CButton;
  new_button->Create("Caption", WS_CHILD | WS_VISIBLE, this->new_button_rect_, 
                     this, this->next_id_++);
}

Then my question would be: How could I handle messages from this button? Is it possible to use the MFC message map facility?

The solution should work in both vs6 and vs2005.

Thank you!

Answer 1

These are the solutions I’ve found so far in order of relevance:

1. Use ON_COMMAND_RANGE if you can define the range of the control IDs you want to handle.

2. Overload CWnd::PreTranslateMessage() and do whatever stuff you want with the messages received. NOTE: When dealing with buttons, take into account that the BN_CLICKED event is NOT sent to PreTranslateMessage but directly sent to the window procedure.

3. Overload CWnd::WindowProc() and do whatever stuff you want with the messages received. NOTE that when dealing with buttons this is the ONLY WAY I’ve found to handle the BN_CLICKED event.

Interesting links:

• Please help with PreTranslateMessage and user defined messages handling.
• TN006: Message Maps

I hope this helps… thank you all for your contributions.