Hello,
It seems the behavior is related to using the BusyIndicator control. Here is a very slimmed down version of our application.
At startup, we typically create 5 RadTabItem controls. Each TabItem contains a Canvas; each canvas can have scores of user controls added to it.
We dismiss the BusyIndicator when we have finished populating the ViewModels and creating all the View controls. I don't know what the exact threshold for the number of tabs/usercontrols is, but at a certain point the BusyIndicator is slow to dismiss, and the Rad controls - buttons, docking pane tabs, tabitem tabs, etc, are drawn as though disabled. When mouse cursor moves over them, they are drawn in their correct state.
If we don't use the BusyIndicator, but use a Wait cursor instead, we don't see the strange gray behavior.
However, there is a problem using the wait cursor: it is difficult to know when all the tabitems are fully populated and displayed.
We have tried hooking RadTabItem.Loaded for each tab item, and changing the cursor when we count the correct number of tabs has been created. However, this doesn't work as expected. We have tried hooking RadTabControl.Loaded; it, too, fires the Loaded event before everything is drawn and ready.
Any suggestions how to solve either of these problems would be appreciated...