UIApplication Properties

Name	Return Type	Description
P ActiveAddInId	AddInId	Get current active external application or external command id.
P ActiveUIDocument	UIDocument	Provides access to an object that represents the currently active project.
P Application	Application	Returns the database level Application represented by this UI level Application.
P DrawingAreaExtents	Rectangle	Get the rectangle that represents the screen pixel coordinates of drawing area.
P IsValidObject	Boolean	Specifies whether the .NET object represents a valid Revit entity.
P IsViewerModeActive	bool	Obsolete. Determines if Revit session is in Viewer mode.
P LoadedApplications	ExternalApplicationArray	Returns an array of successfully loaded external applications.
P MainWindowExtents	Rectangle	Get the rectangle that represents the screen pixel coordinates of the Revit main window.
P MainWindowHandle	IntPtr	Get the handle of the Revit main window.
P ProductIsRS	bool	Identifies if the current Revit product has an RS designation. Most add-ins will not need to use this information.