To display images for nodes, you must first make the images available to the tree view field. Then you specify the images to use for each node. A tree view node can have several images associated with it.
The item image is displayed with the node.
The state image is displayed next to the node image. In the following illustration, the check box next to each node is a state image.
Overlay images allow you to add to the node image without requiring several versions of the icon. For example, an overlay image containing a slash could be placed on top of a folder icon, indicating the item can’t be accessed.