The root item for the toplevel collection of items in a tree oriented item structure. From a data structural point of view, trees should always be single rooted, even though trees in a UI often appear to be multi-rooted. Therefore, the RootItem of the NavControl is hidden from the user and API, but can be utilized when the tree needs to be treated as a single rooted tree.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
