FocusManager.GetFocusedElement Method (DependencyObject)
Gets the element with focus within the specified focus scope.
Assembly: System.Windows (in System.Windows.dll)
Generally there is only a single focus scope in a Silverlight application. However, modal dialogs and popups can introduce additional focus scopes, in which case using the overload that enables specifying the scoping object might be necessary.
In the current implementation, passing an element parameter value that is not of type Window will result in a returned value of null.
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.