I working on an app where I would like to have a Window with a single TabControl and a single RadDocking control in each one of its TabItems. This works as long as the docking control is the content of the TabItem control. As soon as something comes in between the two (such as the Grid control in the sample code), the exception below is thrown. Do you know if this scenario is possible? I'm using 2010 Q1.
System.InvalidOperationException: Specified element is already the logical child of another element. Disconnect it first.
at System.Windows.FrameworkElement.ChangeLogicalParent(DependencyObject newParent)
at MS.Internal.FrameworkObject.ChangeLogicalParent(DependencyObject newParent)
at System.Windows.FrameworkElement.AddLogicalChild(Object child)
at System.Windows.Controls.ContentControl.OnContentChanged(Object oldContent, Object newContent)
at System.Windows.Window.OnContentChanged(Object oldContent, Object newContent)
at Telerik.Windows.Controls.Docking.FakePopupWindow.OnContentChanged(Object oldContent, Object newContent)