Example

The DevExpress ASP.NET Callback Panel (ASPxCallbackPanel) is a lightweight web control that allows you to dynamically update its content using callbacks, preventing undesirable entire page postbacks. You can initiate an update callback by calling the PerformCallback client method.

The ASPxCallbackPanel content remains visible while its callback is being processed on the server. During callback processing, the panel control can be covered with a customizable Loading Panel and Loading Div elements. The appearance and functionality of the Loading Panel can be defined using the LoadingPanel and SettingsLoadingPanel properties. The Loading Div's style is customized using the LoadingDiv property.

In this example, ASPxCallbackPanel is used to display detail information on an employee selected within a list box. When the selected item in the list box is changed, ASPxCallbackPanel's PerformCallback client method is called to initiate a callback to update the panel content. On the server side, the selected list item's value is used as an SQL SELECT query parameter's value, and as a result, ASPxCallbackPanel displays the requested information.

The EnableCallbackAnimation check box specifies whether a specific animation effect is used when a callback panel's content is updated using a callback.