Use this method to reinitialize the data source after making changes to the ItemSource.
This method triggers the InitializeAsyncCompleted
This method causes any currently expanded rows or columns to be collapsed.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, 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