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We have received the following report from 2 of our customers regarding the application that uses the Prof-UIS lib.

Still having the issue with this version where the desktop of the computer continually "flickers" when the mouse is being moved within the PhatPad application window. Movement outside the window of the PhatPad application does not produce this "flicker", even while the PhatPad application is still running. I don’t know if this "flicker" is due to a screen refresh issue or not.

Actually, we recently switched from the Stingray framework to ProfUI for this app and this particular version uses the latest library 2.62, but originally it was reported when we’ve used 2.60. We have not seen this behavior, but it is definitely attributed to the UI lib. Is this a known issue? Are there any specific VGA adaptors/drivers that may experience this behavior?

Thanks.

Thanks. Surly, weaˆ™ve checked for all that already. As I mentioned, we could not reproduce this error and only one out of 500+ beta testers reported the this problem. Bu I decided to ask just in case.

Did you try to analyze what is special with that computer where the problem occurs?

Here are details of customer’s computer:

I went from 32 to 16 bit color, and the desktop as well as other picts in other apps, all still flicker. The drawing in Phatnotes now has been duplicated a little off center, as if having a shadowing effect. I put it back to 32 bit color, and the drawing returns to normal. The flickering persists.

Here’s what I have on my machine:
Video Card: Radeon X600 SE HyperMemory 256 MEG
Processor: Pentium D 830 Dual Core 3GHz
OS: XP Media Center 2005 Edition
Hard Drive: 80 GB ATA 7200RPM with DataBurst Cache

I also turned off my Firewall, Anti-spy, anti-virus, and anti-spyware in succession, and no change. But I’ll keep thinking about it as I work on the docs.

Also, could this relate to this:

Flashes of black

A related issue happens when applications do painting that’s not part of a WM_PAINT. USER detects the application is drawing and redraws the desktop, but the application may not have finished drawing the hwnd when that happens, and the result is the backing bitmap contains uninitialized pixels (black). Again, Microsoft is actively working in this area so please send in your feedback on where you think improvement is needed.

See: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnlong/html/AppComp.asp

You can make the desktop flicker by repainting the desktop window but we do not repaint the desktop and nobody reported a similar problem. Did you try to reproduce the problem using our samples? Do you use the PC desktop or some terminal desktop? Do you have any additional information about this problem?

To localize the source of problems of this kind, you should exclude the functionality in your project part by part until problem the disappears. We would also recommend you to start looking for the source of the problem by analyzing all invocations of the RedrawWindow(), DeferWindowPos() and SetWindowPos() APIs. If any receives NULL in the HWND parameter, this may cause desktop flickering.