TNotebook.PageIndex property

Member of TNotebookpublishedIn unit ExtCtrls

Ordinal position for the active page in the notebook control.

Declaration

pascal

property PageIndex: Integer read GetPageIndex write SetPageIndex default - 1;

Description

PageIndex is an Integer property that indicates the ordinal position for the active page in the notebook control.

A value assigned to the property must must be in the range -1 to the number of defined Pages - 1. No actions are performed in the method when the new value for PageIndex is not in the required range.

Setting the value in the property causes the active page object to be hidden; it is hidden at run-time and design-time using the Visible and ControlStyle properties. The OnBeforeShow event handler in the newly selected page object is signalled (when assigned). The page object is displayed by updating its Visible, ControlStyle, and Align properties.

The default value for the property is -1, and indicates that a page is not currently selected or available.

An experiment, built from Lazarus main 2dfa93c66e of 10-22-2026. Not the official Lazarus documentation.