To expand or collapse a row, use the row's Expanded property. To expand or collapse all the rows of a grid or a specific row collection use the RowsCollection's RowsCollection.ExpandAll and RowsCollection.CollapseAll methods.
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