C / C++ / MFC Discussion Boards

si_695-Apr-07 1:05

5-Apr-07 1:05

Hi
I have a modeless dialog which i use as a wait screen, with a progress bar on it

so when something is happening in my application, the wait screen is displayed and the progress bar moves across giving the indication of how much time is left to wait

i have added a cancel button to the modeless dialog, so when the user clicks it it stops the process

im using this

ShowModelessDaig();

for (int f=0; f< mylist.GetItemCount(); f++)
{
// do some stuff
// Update Progress bar

}
CloseModelessDiag();

my problem is that i cant seem to click the cancel button on the modeless dialog, for testing purposes i was trying to display a messagebox when cancel was being clicked, but the OnBnClicked function is not even being called

How can i set focus to the cancel button

i hope all that makes sense and is clear

Simon

Re: modeless dialog

Naveen5-Apr-07 1:21

Naveen

5-Apr-07 1:21

When you click on the button it actually sends a message. But when you are in the for loop, your application will not process any message.

The only solution is to do the task in the "for loop" in a seperate thread.

nave

Re: modeless dialog

James R. Twine5-Apr-07 1:58

James R. Twine

5-Apr-07 1:58

   Naveen is correct in that you are not pumping any messages, so with no message flow, your button has no way to indicate that it has been clicked.

   A BG thread is the modern way to do it, but you have to be a bit careful if mixing MFC objects and threads. The Old School way to do it is to pump messages inside of your for(...) loop. It may be considered kludgy, but if you ensure that the user cannot activate any other functionality that might break what you are working on, that would be one way to do it.

   For example, something along the lines of the following (may need work):

for (int f=0; f< mylist.GetItemCount(); f++)
{
   MSG msgMSG;
 
   if( ::PeekMessage( &msgMSG, hWndOfModelessDlg, 0, 0, PM_REMOVE ) )
   {
     ::TranslateMessage( &msgMSG );
     ::DispatchMessage( &msgMSG );
   }
   // do some stuff
   // Update Progress bar
}

Peace!

-=- James
Please rate this message - let me know if I helped or not!<HR>If you think it costs a lot to do it right, just wait until you find out how much it costs to do it wrong!
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Re: modeless dialog

Mark Salsbery5-Apr-07 8:47

Mark Salsbery

5-Apr-07 8:47

Hola James,

I don't think it's kludgy if one understands message loops. Message loops are our responsibility.
It's been that way from the start. MFC hides it from us so it seems alot of us forget we're in
charge of message processing.

For MFC, sometimes CWinThread::PumpMessage is more appropriate
than ::TranslateMessage/::DispatchMessage. Then the pretranslatemessage processing and any
other CWinThread/CWnd shenanigans gets done Smile | :)

. Of course, that may not be the desired effect and
at times it's appropriate to bypass the CWinThread message loop processing and eat all the
messages (I do that when "rubberbanding").

for (int f=0; f< mylist.GetItemCount(); f++)
{
   // Pump all queued messages
   MSG msg;
   while (::PeekMessage( &msg, NULL, 0, 0, PM_NOREMOVE)) 
   { 
      if (!AfxGetApp()->PumpMessage()) 
      { 
         break; 
      } 
   }
 
   // do some stuff
   // Update Progress bar
}

Piece,
Mark

"If you can dodge a wrench, you can dodge a ball."

hello

aarti sharma5-Apr-07 0:47

aarti sharma

5-Apr-07 0:47

i m aarti want a question 4 only c