Professional ASP.NET 3.5 AJAX

7.3. ASP.NET AJAX Control Toolkit Server Controls

The next set of ASP.NET AJAX controls actually do not always extend other ASP.NET controls, but instead, are controls themselves. The following sections details these controls.

7.3.1. Accordion Control

The Accordion control is used to specify a set of panes, similar to the famous menu in Microsoft Outlook. Each pane is made up of a header template and a content template. The header templates of all panes are always visible, while only one content template is visible. The user selects which pane to view by clicking the header. The content from the previously active pane is hidden from view, and the content of the newly selected pane is displayed instead.

The Accordion control can provide a fade transition when switching among active panes. You set the FadeTransitions property to true and can set the TransitionDuration and FramesPerSecond values. The default values are 250 milliseconds and 40 frames per second, respectively.

The SelectedIndex property lets you declaratively and programmatically control which pane to show. Other important properties are the AutoSize and Height properties. The AutoSize property is None by default, meaning that the size of the Accordion control changes based on the active pane. Other content on the screen may be shifted to accommodate the changing size. However, when the AutoSize property is set to Limit, the size is restricted to the Height value. The active pane displays scrollbars if the content ...