Hi william83,
surround the controls with a UpdatePanel:
<%@ Page Language="vb" AutoEventWireup="false" CodeBehind="Test1.aspx.vb" Inherits="SoluTest_CollapsiblePanel.Test1" %>
<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="cc1" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<link href="StyleSheet.css" rel="stylesheet" type="text/css" />
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:ScriptManager ID="ScriptManager1" runat="server" />
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:Button ID="Button1" runat="server" Text="To post back" />
<div class="collapseContainer">
<asp:Image ID="btnSearchImage" runat="server" ImageAlign="Right" ImageUrl="~/Images/expand_blue.jpg" />Ajax
<asp:Label ID="lblSearchText" runat="server" Text="Label">(Advance Search)</asp:Label>
<asp:Panel ID="pnlSearch" runat="server" CssClass="collapsePanel">
<asp:Image ID="Image2" runat="server" ImageUrl="~/Images/AJAX.gif" ImageAlign="Right" />
ASP.NET AJAX is a free framework for building a new generation of richer, more interactive,
highly personalized cross-browser web applications.
</asp:Panel>
</div>
<cc1:CollapsiblePanelExtender ID="pnlSearch_CollapsiblePanelExtender" runat="server"
Enabled="True" TargetControlID="pnlSearch" CollapsedSize="0" Collapsed="true"
TextLabelID="lblSearchText" CollapsedText="Advance Search" ExpandedText="Advance Search"
ExpandControlID="btnSearchImage" CollapseControlID="btnSearchImage" AutoCollapse="false"
AutoExpand="false" EnableViewState="true" ExpandDirection="Vertical" SuppressPostBack="true"
ImageControlID="btnSearchImage" CollapsedImage="~/Images/expand_blue.jpg" ExpandedImage="~/Images/collapse_blue.jpg">
</cc1:CollapsiblePanelExtender>
</ContentTemplate>
</asp:UpdatePanel>
</div>
</form>
</body>
</html>
Have my code helped?
Best regards,
Zhi-Qiang Ni