StartEditMode enters the editor into edit mode.
Note: Typically there is no need to call this method directly. The editor will automatically enter and exit edit mode as necessary. For example, when using the editor embedded inside a field of a XamDataGrid, the editor is put into edit mode automatically when the cell is clicked and exits edit mode when the focus leaves the cell. When using the editor as a stand-alone control, the editor will automatically enter edit mode when the editor receives focus (for example via a mouse click or when tabbing into it) and exit edit mode when the editor looses focus. This default behavior can be controlled using the IsAlwaysInEditMode property.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, 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