Represents the selection context with objects that model the selection below the project item level. For example if a designer was open for a given project item, then this collection would hold any objects representing selected controls or other items in the environment.
Remarks
The SelectionContainer object is a generic selection tracking object. There is one global selection context for the environment, DTE.SelectedItems.SelectionContainer. Because an item can include any type of object within its context, the SelectionContainer object can represent any type of selected object.