Want to win a PS4? Go Premium and enter to win our High-Tech Treats giveaway. Enter to Win

x
?
Solved

Force Window Redraw

Posted on 2003-11-07
5
Medium Priority
?
4,602 Views
Last Modified: 2013-11-20
Hi,

I have a window that has a progress bar that's supposed to show progress during a long calculation. It works fine except if you place another window over it then remove it - it never receives anymore paint messages. I've tried a list of different functions including :

InvalidateWindow(), UpdateWindow(), RedrawWindow().. then SendMessage(WM_PAINT, 0, 0).

I used these in the function that updates the progress bar so everytime it moves it should redraw its window. But this never occurs and the window will just remain white. Is there any way to really force it to redraw - I thought SendMessage() would not let the program continue until that message was processed?

Thanks
0
Comment
Question by:ragin_cajun
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
  • 2
5 Comments
 
LVL 48

Expert Comment

by:AlexFM
ID: 9706200
Invalidate();
UpdateWindow();

This is a way to force window redraw. When you move another window above your window, Windows invalidates your window. Possibly your window doesn't handle WM_PAINT message. Please show your code - how do you draw progress bar.
0
 
LVL 1

Author Comment

by:ragin_cajun
ID: 9707221
This is basically how my progress bar function will run, all the different methods I tried to use are below:

void CProgressDialog::UpdateProgressBar(int i)
{
    // Set progress bar
    progress_control.SetPos(i);
    i++;
   
    // try 1
    Invalidate();
    UpdateWindow();

    // try 2
    RedrawWindow(0, 0, RDW_UPDATENOW);

    // try 3
    SendMessage(WM_PAINT, 0, 0);

    // try 4 - perhaps update parent instead?    
    CWnd *pParent;
    ::InvalidateRect(pParent->GetSafeHwnd(), NULL, 1);
    ::UpdateWindow(pParent->GetSafeHwnd());

    // try 5
    ::SendMessage(h->GetSafeHwnd(), WM_PAINT, 0, 0);

    // try 6
    ::RedrawWindow(h->GetSafeHwnd(), NULL, NULL, RDW_UPDATENOW);

    // Still no results!!! Window remains unpainted after moving another window above.
}


0
 
LVL 48

Expert Comment

by:AlexFM
ID: 9707560
Read this thread, possibly this may be also your problem:

http://www.experts-exchange.com/Programming/Programming_Languages/MFC/Q_20791684.html
0
 
LVL 3

Accepted Solution

by:
freewell earned 220 total points
ID: 9711935
Inside your calculation loop, add the following codes to allow windows to process the invalidate messages.

MSG msg;
while(bLoop)
{
  // Your loop processing

  pWnd->Invalidate(TRUE);
  while(PeekMessage(&msg,NULL,0,0,PM_REMOVE))
  {
      TranslateMessage(&msg);
      DispatchMessage(&msg);
  }
}
0
 
LVL 1

Author Comment

by:ragin_cajun
ID: 9712315
That's what I was missing, it worked perfectly, thanks
0

Featured Post

Tech or Treat! - Giveaway

Submit an article about your scariest tech experience—and the solution—and you’ll be automatically entered to win one of 4 fantastic tech gadgets.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

In this article, I'll describe -- and show pictures of -- some of the significant additions that have been made available to programmers in the MFC Feature Pack for Visual C++ 2008.  These same feature are in the MFC libraries that come with Visual …
Introduction: Hints for the grid button.  Nested classes, templated collections.  Squash that darned bug! Continuing from the sixth article about sudoku.   Open the project in visual studio. First we will finish with the SUD_SETVALUE messa…
This video will show you how to get GIT to work in Eclipse.   It will walk you through how to install the EGit plugin in eclipse and how to checkout an existing repository.
In this video, Percona Solution Engineer Rick Golba discuss how (and why) you implement high availability in a database environment. To discuss how Percona Consulting can help with your design and architecture needs for your database and infrastr…
Suggested Courses

618 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question