i want to open a RadWindow with an AutoCompleteBox on it. When i get back to my user control i want
to read the Searchtext from the AutoCompletexBox! I can't find an example or something helpful.
You could check here how to use RadWindow as a UserControl - you just need to place the AutoCompleteBox in the UserControl and bind its SelectedItem property to a property of the UserControl. After that subscribe to the Closed event of the Window and in its event handler get the SelectedItem.
I have attached a simple project to demonstrate the approach, hope it helps.