Thank you for your honest feedback.
Yes, this behavior is undesired, and we apologize for it. We have been trying to locate the problem for these repainting issues for nearly two years now, with little success. In some cases a simple restart of the machine fixed the issue (as described below). In others, the problem turned out to be in old video drivers, and yet in others, the issues were in the Citrix terminal server system. These resolutions suggest that this issue might not be directly related with RadControls for WinForms but with the specific GDI/RDP context.
We are determined to understand why it is happening and what we can do to overcome it. We will very much appreciate it if you would answer the following questions for us in order to help us pinpoint the problem:
- Are the described glitches present on all the machines that remotely connect to the application or on some of them? If some, what are the specifics/differences between them?
- What are the hardware specifications?
- What is the OS installed on these machines?
- Are you running Citrix? If yes, what version?
- Are the machines up to date in terms of drivers? We have had a couple of customers solve similar issues with simple video driver update from the original manufacturer (rather than using the Microsoft driver).
- Are the machines up to date in terms of software updates?
- Are the machines running DirectX 10?
- It is possible that this issue is somehow related to the fact that we use GDI-based animations. We believe that this might be a problem related to GDI and RDP, and the way the RDP transfers painting information - in other words, the only way you can prevent this from happening is to turn off the animations in our controls (which is pretty simple). We have prepared a few scenarios you could perform and help us narrow down the issues that might lead to this.
I would like to ask you to try turning off the Bitmap Cache we use when painting gradients and see whether the issue persists (very important case):
Me.RadGridView1.Behavior.BitmapRepository.DisableBitmapCache = True
After doing this, if the issue persists, you will be able to overcome it by turning off the animations for all controls:
ThemeResolutionService.AllowAnimations = False
or the animations for a separate control:
Please write back when you have experimented with the scenarios described above letting us know which of them is helpful.
Thanks for you time. We look forward to receiving further details on that case.
the Telerik team
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