The TreeNode class represents a single data item in a Tree object. Each TreeNode displays as a text label, and optionally a bitmap icon and a checkbox. The icon and checkbox appear to the left side of the text label. The icon can be used in one of two ways:

The rectangular area that encloses the text label and the icon, if present, is the “hit zone” for the node, the region that responds to mouse actions by triggering events for which that node is the TreeViewField's triggernode or curnode.

A TreeNode that has child nodes is referred to as a parent node. Child nodes, when displayed within a TreeviewField, are indented below their parent node. A node can also have sibling nodes that are all indented at a same distance.

You can use the ClientData Attribute) inherited from the Object class to associate application-specific data to each node. You can use the keylabel (which is not displayed) to uniquely identify each node.