This property manages an array of strings where each string uniquely identifies a layer (these string identifies should correspond to the LayerID property of ILayer). During the processing of layers, the FillSceneGraph is called on each layer in the order it's Layer ID appears in the UserLayerIndex. Layers listed towards the end of this string array are therefore rendered last, and effectively appear in the foreground.
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