Populating
TreeViews
Contents
You must write a script to add items to a TreeView. You cannot add
items in the painter as with other list controls. Although you can
populate all the levels of the TreeView at once, TreeView events allow you
to populate only branches the user looks at, which saves unnecessary
processing.
Typically, you populate the first level of the TreeView when the
control is displayed. This code might be in a window’s Open event, a user
event triggered from the Open event, or the TreeView’s Constructor event.
Then a script for the control’s ItemPopulate event would insert an item’s
children when the user chooses to expand it.
The ItemPopulate event is triggered when the user clicks on an
item’s plus button or double-clicks the item, but only if the item’s
Children property is TRUE. Therefore, when you insert an item that will
have children, you must set its Children property to TRUE so that it can
be populated with child items when the user expands it.
You are not restricted to adding items in the ItemPopulate event.
For example, you might let the user insert items by dragging from a
ListBox or filling in a text box.