.NET winforms redraw problem

[SEngel]

I am using .net 2.0 and working in VS2005.
I've noticed following unpleasant effect in the standard Form class
behaviour: when the Form is hovered by some other window, it is being redrawn very slowly.

Here is the example. I have taken empty form, put there some standard controls:
http://www.ljplus.ru/img4/b/o/boshetunmaj/Redraw2.jpg

My hardware conf is: p4 3200, 2 Gb ram, GeForce 5200.

[SEngel]

I have found that controls redraw at this moment takes up to 80% of CPU time...

[Plater]

I have never had that occurance unless my computer is super bogged down with a lot of applications.
Might I suggest checking your windows theme/style settings? The P4 might not be able to hand it if you have a LOT of controls on your windows.

[SEngel]

I have never had that occurance unless my computer is super bogged down with a lot of applications.
Might I suggest checking your windows theme/style settings? The P4 might not be able to hand it if you have a LOT of controls on your windows.

It's strange, but there are only few controls. The most noticable effect is for TextBoxes, ComboBoxes and GroupBoxes.
Which one setting do you mean?

[Plater]

Hmm, I turn off most of the themeing on my computer so I'm not sure it even has any bearing on it.

Are you doing anything else with the form? Doing anything durring paint/redraw events? Or populating data from a database or anything?

[SEngel]

Hmm, I turn off most of the themeing on my computer so I'm not sure it even has any bearing on it.

Are you doing anything else with the form? Doing anything durring paint/redraw events? Or populating data from a database or anything?

The form is free from any code.

I have set DoubleBuffered property of groupboxes to true and this helped a little, but the problem still stays.

[SEngel]

I have found the following effect:
I create multi window app (I run another window in another thread) and catch
events concerning moving and resizing of that other window. On each such event I run DoEvents() in a main thread. This leads to perferct window redraw.

But I can't understand, how to do the same with windows of 3rd side applications.
Can anybode help?

[Plater]

Ah!
So this window was not running in the GUI thread but in a different thread?

[SEngel]

Ah!
So this window was not running in the GUI thread but in a different thread?

Yes, I've created BackgroundWorker in the main GUI thread and asked it to do
Run.Application(AnotherWindow);

In this case I've no such awful effect as it was described in the 1st post.
That's because I can catch events from this window.

[Plater]

I thought you were having trouble with the "main" window. Makes sense that the window in the other thread had trouble with redraws.

[SEngel]

I thought you were having trouble with the "main" window. Makes sense that the window in the other thread had trouble with redraws.

No, you were right!
again, the situaton is following:

1). I have main window with simple controls. When any window from other app hovers over it, the problem with redraw occurs.
2). I have another window in another thread. There is no problem described in point 1), if I catch it's Move and Resize events in the main window and refresh main window manually by means of DoEvents()
-----------

So, how can I get rid of the problem in point 1) ???

[Plater]

Did you use Application.Run() to run the main form?

[SEngel]

Did you use Application.Run() to run the main form?

Yes,

Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(fals e);
Application.Run(new PhotoEngineForm());

[Plater]

And PhotoEngineForm is the one that has troubles with the screen not getting refreshed?
And this only occurs when that otherr form in that other thread is open correct?

[SEngel]

And PhotoEngineForm is the one that has troubles with the screen not getting refreshed?
And this only occurs when that otherr form in that other thread is open correct?

PhotoEngineForm is the main form with refresh problems, that is correct.
But troubles occur, when the other application window is moved over PhotoEngineForm.

I have written about other form, let's call it OtherForm, ONLY in order to show, that the problem is theoretically solvable be means of catching onMove and onResize events. (this also means, that my hardware conf can handle it). But I don't know how to catch these events from OTHER applications.

[Plater]

Well for some reason it seems like your PhotoEngineForm is not getting it's WndProc messages (Windows Messages).
Have you tried overriding that function and dolling out the refresh commands on the correct windows messages?

Either that or I would create a new Form, copy the code into it and set THAT as your main form and see if the results repeat?

[SEngel]

Well for some reason it seems like your PhotoEngineForm is not getting it's WndProc messages (Windows Messages).
Have you tried overriding that function and dolling out the refresh commands on the correct windows messages?

Either that or I would create a new Form, copy the code into it and set THAT as your main form and see if the results repeat?

Yes, it looks like the form doesn't handles repaint events properly.
Can you advice, which method should I override?

I'll upload source code soon... But this effect doesn't take place on every PC. It looks like .NET forms on PCs with newer video adapter and CPU work perfectly...

[Plater]

What happens if you don't do this:
Application.EnableVisualStyles();

It should no longer attempt to match the "theme" of your computer settings (I think).
See if that makes a difference?

[SEngel]

What happens if you don't do this:
Application.EnableVisualStyles();

It should no longer attempt to match the "theme" of your computer settings (I think).
See if that makes a difference?

I have commented this line, but It doesn't help :(

Here is the example of simple application with the screen from my computer (that is not PhotoEngineForm, but as you can see, there are troubles here too):
http://rapidshare.com/files/100541360/WindowsApplication1.rar.html

[vijayB]

Try to rebuild the solution and create it's executable. The problem might be the loading/unloading of VS2K5 environment

I am using .net 2.0 and working in VS2005.
I've noticed following unpleasant effect in the standard Form class
behaviour: when the Form is hovered by some other window, it is being redrawn very slowly.

Here is the example. I have taken empty form, put there some standard controls:
http://www.ljplus.ru/img4/b/o/boshetunmaj/Redraw2.jpg

My hardware conf is: p4 3200, 2 Gb ram, GeForce 5200.

[Plater]

I did not see anything different about that application then any other.
It was "funny" while I was dragging the window (my system is under heavy load) but as soon as I stopped moving it was fine.
I tested and Visual Studio and all my other windows exhibited the "funny" behavior while I was moving the window. I think it was certainly related to my system being under load.

[SEngel]

I did not see anything different about that application then any other.
It was "funny" while I was dragging the window (my system is under heavy load) but as soon as I stopped moving it was fine.
I tested and Visual Studio and all my other windows exhibited the "funny" behavior while I was moving the window. I think it was certainly related to my system being under load.

What hardware conf do you have?

[Plater]

Pentium D 2.8Ghz with 1 gig ram.
Nothing great.
I also had THREE visual studios open as well as a bunch of IEs Firefox(who is a pig and takes up like 100megs virtual memory) and MS SQL Server Management, along with a few other things.

[SEngel]

Pentium D 2.8Ghz with 1 gig ram.
Nothing great.
I also had THREE visual studios open as well as a bunch of IEs Firefox(who is a pig and takes up like 100megs virtual memory) and MS SQL Server Management, along with a few other things.

and what video adapter do you have?

[Plater]

It appears to be generic:
"Intel(R) 82945G Express Chipset Family" is all it says.