Solved

How to force a WPF Control to Refresh mid-processing

Posted on 2006-11-24
6
5,938 Views
Last Modified: 2012-06-27
Peace be with you all,

In trying to adapt to the new WPF model, I have not figured out how to update a
control in the midst of processing.

--------------
//non-complete example:

Button buGo;
TextBlock tbOutput;

private void buGo_Click( object sender, RoutedEventArgs e ) {
  int i;
  for (i=0; i < 1000; ++i) {
    tbOutput.Text = i.ToString();
}
--------------

After clicking on buGo, the program runs and then tbOutput changes to '999'.
What I want is to see each individual number '0' ... '999' in tbOutput after
each modification, even if I have to make a fct call manually after setting
tbOutput.Text.

In System.Windows.Forms, I could call tbOutput.Refresh() which would
force the control to re-render itself immediately.

I am having no luck finding a corollary in the WPF and am guessing that
some sort of threading solution may be the only way to accomplish this,
meaning that I may have to split out my processing into a second thread,
which makes an 'Invoke'-ish type call back to the original thread that
created the controls.

Thanks in advance,
Robert McCall

PS: *MODERATORS* Might I suggest 3 new .NET sub-categories:  WPF, WCF and WF/WWF?
   Now that Microsoft has officially released .NET 3.0, these questions are gonna start flooding in, maybe.
0
Comment
Question by:mihrlogic
[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
6 Comments
 
LVL 48

Expert Comment

by:AlexFM
ID: 18010526
Does Application.DoEvents help?
0
 

Author Comment

by:mihrlogic
ID: 18010622
AlexFM,

No, there is no such call in the WPF ~ Windows Presentation Foundation.  It's a completely
different model; and, FYI, Application.DoEvents() exposes your program to all kinds of problems
with re-entrancy, so it is better to use Obj.Refresh() instead.

Thanks anyway,
Robert
0
 
LVL 48

Accepted Solution

by:
AlexFM earned 500 total points
ID: 18010691
Try Dispatcher.UpdateRender(). In any case, you need to add some kind of sleep to this code to see that something changes.
Of course, threading is better solution. WPF has some kind of Invoke methods which allow to talk with WPF controls from worker threads - exactly like in Windows Forms.

In cheap DoEvents solution, reentrance problems are solved by disabling some UI elements. This is some information about WPF DoEvents:
http://shevaspace.spaces.live.com/blog/cns!FD9A0F1F8DD06954!411.entry?_c11_blogpart_blogpart=blogview&_c=blogpart#postcns!FD9A0F1F8DD06954!411
0

Featured Post

PeopleSoft Has Never Been Easier

PeopleSoft Adoption Made Smooth & Simple!

On-The-Job Training Is made Intuitive & Easy With WalkMe's On-Screen Guidance Tool.  Claim Your Free WalkMe Account Now

Question has a verified solution.

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

In my previous two articles we discussed Binary Serialization (http://www.experts-exchange.com/A_4362.html) and XML Serialization (http://www.experts-exchange.com/A_4425.html). In this article we will try to know more about SOAP (Simple Object Acces…
Many of us here at EE write code. Many of us write exceptional code; just as many of us write exception-prone code. As we all should know, exceptions are a mechanism for handling errors which are typically out of our control. From database errors, t…
This is a high-level webinar that covers the history of enterprise open source database use. It addresses both the advantages companies see in using open source database technologies, as well as the fears and reservations they might have. In this…
NetCrunch network monitor is a highly extensive platform for network monitoring and alert generation. In this video you'll see a live demo of NetCrunch with most notable features explained in a walk-through manner. You'll also get to know the philos…

707 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