public class PreviewControl : UserControl, 
	IDisposable

Public Class PreviewControl _
	Inherits UserControl _
	Implements IDisposable

public ref class PreviewControl : public UserControl, 
	IDisposable

The dialog or form or window host this preview control must be modal. The view can be any graphical view but not a non-graphical view. And only one can be active. The view can be manipulated by embedded view cube and the visibility and graphical settings set on the view will be evident in the preview control.

SystemObject
  System.Windows.ThreadingDispatcherObject
    System.WindowsDependencyObject
      System.Windows.MediaVisual
        System.WindowsUIElement
          System.WindowsFrameworkElement
            System.Windows.ControlsControl
              System.Windows.ControlsContentControl
                System.Windows.ControlsUserControl
                  Autodesk.Revit.UIPreviewControl