Postback Events Sample The C1Expander inside an UpdatePanel: Refreshing UpdatePanel1... Header Vestibulum ut eros non enim commodo hendrerit. Donec porttitor tellus non magna. Nam ligula elit, pretium et, rutrum non, hendrerit id, ante. Nunc mauris sapien, cursus in. The C1Expander outside of the UpdatePanel: Header Vestibulum ut eros non enim commodo hendrerit. Donec porttitor tellus non magna. Nam ligula elit, pretium et, rutrum non, hendrerit id, ante. Nunc mauris sapien, cursus in. Description This sample demonstrates the behavior of the C1Expander control during full and partial page postback. This sample page includes two expander controls. The first expander control is located inside an UpdatePanel, and the server-side ExpandedChanged event is set to "C1Expander1_OnExpandedChanged". The second expander control is located outside of the UpdatePanel, and the server-side ExpandedChanged event is set to "C1Expander2_OnExpandedChanged". When the ExpandedChanged event handler is added, the C1Expander control posts back to the server whenever the content pane is expanded or collapsed. Note, if you wish execute postback without using the ExpandedChanged event, you can set the AutoPostBack property to True. Documentation