TCustomTreeView.OnChanging

Event handler signalled before the selected node in the tree view control is changed.

Declaration

Source position: comctrls.pp line 3647

Description

OnChanging is a TTVChangingEvent property with the event handler signalled prior to changing the selected node on the tree view control. It allows an application to determine whether the new tree node can become the selected node for the control.

Node is the tree node to examine in the handler routine.

Set the AllowChange argument to True to allow the tree node to be the selected node on the control.

OnChanging is signalled from the CanChange method, and occurs when a new value is assigned to the Selection property.