The RadWindow control is not meant to be placed inside the layout - it should be used as a root tag only (like shown in our online examples). Anyway, when the window is shown it is not in the layout anymore, so it cannot be placed inside a Canvas and because of this it cannot be restricted to it.
The IsRestricted property restricts the Window to the Silverlight application, but it can be customized - there is a RestrictedAreaMargin property that is of type thickness and describes the restricted are using a margin from the Silverlight plugin.
You can use the RestrictedAreaMargin property to set a margin that will limit the Maximized position of RadWindow. It will also affect the dragging of the RadWindow since the control will be restricted to the margin. To turn on and off this feature you should use the IsRestricted property.
Hope this information helps. If you have any other inquiries please let us know.
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