Solved

indeterminate progress bars

Posted on 2002-07-19
9
620 Views
Last Modified: 2013-11-20
Hi ,
 Does anyone know on how to create indeterminate progress bars in a dialog. I have this big dialog function which will load another DLL and execute functions within it. I need to show in my dialog that a processing is going on. I tried creating a thread and updating the progress control but no luck. It looks like the message pump is blocked until the dialog function is completed. Is there any other way I could implement this

Thanks
Saravana
0
Comment
Question by:vsaravana
  • 4
  • 2
9 Comments
 
LVL 8

Expert Comment

by:fl0yd
ID: 7166105
Using multi-threading is the way to go. I don't know what you did, but you must have made a mistake. Did you create the thread to do the actual work? I assume you created a thread to do the updating of the progress bar. In that case the dialog message-handler isn't called until the function doing the calculations has returned.
0
 

Author Comment

by:vsaravana
ID: 7166835
You are correct, I did create the thread for the progress update. It's difficult as per the previous implementation to move tons of code into a thread.
Is there any other option..??

0
 
LVL 8

Accepted Solution

by:
fl0yd earned 100 total points
ID: 7166939
You could use a CWinThread-function (PumpMessage) that is not really well documented:

void DoEvents() {

    MSG msg = { 0 };
    HWND hwnd = AfxGetMainWnd->m_hWnd;
    while( ::PeekMessage( &msg, hwnd, 0, 0, PM_NOREMOVE ) )
        AfxGetApp()->PumpMessage();
}

Call this function whenever you need to respond to messages. So your code would look like this:

void ThisFunctionTakesForEver() {

    // do some code here
    DoEvents();
    // do some more code...
    DoEvents();
    // and so on...
}

If you use this you won't have to use multithread, which is a very complex field of programming.
0
Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

 
LVL 8

Expert Comment

by:fl0yd
ID: 7166942
ooooops, there was a mistake. The right way to go:

    HWND hwnd = AfxGetMainWnd()->m_hWnd;
0
 
LVL 1

Expert Comment

by:jemax
ID: 7167769
Hi,

you could use CWnd::UpdateWindow it bypasses message queue, so your progress bar will be updated.

HTH,
jemax
0
 
LVL 8

Expert Comment

by:fl0yd
ID: 7167803
UpdateWindow sends a WM_PAINT message if the update region isn't empty -- what good is it if those aren't handled?
0
 
LVL 1

Expert Comment

by:jemax
ID: 7168847
Hi,

forgive me, my stupid comment. I forgot that is not possible to SendMessage into wnd thread from another thread, it would cause to deadlock.

Sorry.
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

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

Here is how to use MFC's automatic Radio Button handling in your dialog boxes and forms.  Beginner programmers usually start with a OnClick handler for each radio button and that's just not the right way to go.  MFC has a very cool system for handli…
Introduction: Dialogs (2) modeless dialog and a worker thread.  Handling data shared between threads.  Recursive functions. Continuing from the tenth article about sudoku.   Last article we worked with a modal dialog to help maintain informat…
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.
Internet Business Fax to Email Made Easy - With eFax Corporate (http://www.enterprise.efax.com), you'll receive a dedicated online fax number, which is used the same way as a typical analog fax number. You'll receive secure faxes in your email, fr…

864 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

Need Help in Real-Time?

Connect with top rated Experts

24 Experts available now in Live!

Get 1:1 Help Now