Gets or sets a value indicating whether plus-sign (+) and minus-sign (-) buttons are displayed next to tree nodes that contain child tree nodes.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
The plus sign and minus sign buttons appear next to the root tree nodes only if the ShowRootLines property value is true. If the plus sign and minus sign buttons are not displayed, no visual cue exists to indicate that the tree node contains child tree nodes and is expandable. The user then must double-click a tree node to determine whether it contains child tree nodes, to expand it, or to collapse it.
The following code example illustrates a customized TreeView. By inheriting the TreeView class, this custom version has all the functionality of a typical TreeView. Changing various property values in the constructor provides a unique appearance. Because the property is set to false, the customized control also overrides the OnAfterSelect method so that nodes can be expanded and collapsed when they are clicked.
A control that is customized in this way can be used throughout an organization, making it easy to provide a consistent interface without requiring the control properties to be specified in each individual project.