Programming Guide - Actian

TreeNode and Tree ClassesHeaderClick EventOccurs when the user clicks one of the column headers of the listview fieldwhen the style is LVFS_DETAIL. The ReasonCode attribute of theFrameExec contains the number of the column. In the listview_example,the listview data is sorted on the HeaderClick event.SetValue EventOccurs when the style is LVFS_DETAIL and the user clicks the text in thefirst column or on the associated bitmap. In the other modes, a SetValueevent occurs when the user clicks either the text or the bitmap. Inlistview_examples, a message is displayed in the frame's status bar whena SetValue event occurs.TreeNode and Tree ClassesThe TreeviewField class has two related classes that you must use to work withit—Tree and TreeNode. Because they are interrelated, before you canunderstand treeview fields you must first understand the Treenode and Treeclasses as described in the following sections.TreeNode ClassAppearanceThe TreeNode class represents a node that contains data for a single node in atree. The following sections describe how its attributes affect a treeview field.When displayed in a treeview field, the following attributes of a treenode affectthe appearance of the node:TextLabelSpecifies the text that is displayed for the nodeBmpLblIndxSpecifies an index into the ImageList array, and specifies a bitmap label forthe node. A treeview field has an attribute ImageList, which is an array ofbitmap objects.SelBmpLblIndxSpecifies an index into the ImageList array, and specifies a bitmap label,which is displayed when the node is selected266 Programming Guide