What do you mean by getting the TileView in a RadExpander? Getting a reference to the control at runtime or getting it to work in general? There should be no problem in either case. However, you should keep in mind that the TileView control does not have a minimal size and if you put it in a container that tries to be as small as possible (e.g. the RadExpander content area) then it will not be shown. To avoid this, simply set a size to the TileView.
Let me know if this helps or you have further questions.
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