views:

348

answers:

3

The title pretty much describes it. If I resize my WPF app so that it stretches over two monitors in a dual monitor setup, and resize it back, there will be a ghost window in the second monitor that does nothing, but is still moved when I move the original window in the first screen.

Has anyone had issues like this? I think its a refresh bug on some OSs (I use WINXP 32 bit), but would like to confirm with the community.

A: 

No. We have a WPF app with which there has been quite some graphics related issues (most solved now I believe) but not this. Maybe a driver issue?

Andreas Magnusson
A: 

This is because AllowsTransparency is set to true. Haven't figured a workaround yet but as soon as I set it to false I didn't see the ghost.

Quade36
A: 

Yes, we get this a lot. Usualy it is related to old hardware (eg. integrated graphics card), but it happens on new as well (eg. quadro NVS 295 with the latest drivers). Sometimes the amount of ghosting depends on the speed the windows is dragged with.

Then again, we can't reproduce it on quadro 450 or 290 so it seems it's a driver issue.

There are 2 ways to solve it - set AllowTransparency to false or disable HW acceleration.

This being said, this is one of the smaller problems we had with WPF in multi-monitor environments...

Hrvoje Prgeša