I am just beginning to experiment with ASP.Net Ajax, and I have been attempting the "Using the ASP.Net UpdatePanel Control Panel with Master Pages" tutorial, with no success.
I believe I have successfully downloaded and installed the AJAX Extensions and the AJAX toolkit -- my initial experiments updating a textbox inside an update panel run as expected. However, when I attempt to incorporate Master pages, here's what happens:
I created a Masterpage, AjaxTestPage.master, as described in the tutorial, with the following code:
<%@ Master Language="VB" %>
<!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>Ajax Test Page</title>
</head>
<body>
<form id="form1" runat="server">
<asp:ScriptManager ID="ScriptManager1" runat="server" >
</asp:ScriptManager>
<div>
Master Page<hr />
<asp:contentplaceholder id="ContentPlaceHolder1" runat="server">
</asp:contentplaceholder>
</div>
</form>
</body>
</html>
The problem occurs when I create a content page using the master page, using the following code:
<%@ Page Language="VB" MasterPageFile="~/AjaxTestPage.master" Title="Untitled Page" %>
<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
Content Page
<asp:UpdatePanel runat="server">
<asp:Calendar runat="server"></asp:Calendar>
</asp:UpdatePanel>
</asp:Content>
I get the dreaded squigglies beneath "UpdatePanel" and "Calendar", with error messages indicating that neither one is a "known element."
I'd appreciate any thoughts on what I might be doing wrong.