Master Page Weirdness - "Content controls have to be top-level controls in a content page or a nested master page that references a master page."
This is weird. I added a brand new Web Application project to my solution in Visual Studio 2008.
Created a master page. Made zero modifications. Created a new webform. Set its master page to the MP I just created.
Still, no modifications. No markup. No user controls. No references. Nothing. However when I try to run it, I get:
Content controls have to be top-level controls in a content page or a nested master page that references a master page.
HttpException (0x80004005): Content controls have to be top-level controls in a content page or a nested master page that references a master page.]
System.Web.UI.MasterPage.CreateMaster(TemplateControl owner, HttpContext context, VirtualPath masterPageFile, IDictionary contentTemplateCollection) +8665016
System.Web.UI.Page.get_Master() +51
System.Web.UI.Page.ApplyMasterPage() +15
System.Web.UI.Page.PerformPreInit() +45
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +282
If I do the same exact thing in a standalone project thats outside of this solution, it works fine. Keep in mind that I'm using a web application project vs a website project if that makes any difference.
The webform:
<%@ Page Language="vb" AutoEventWireup="false" CodeBehind="Default.aspx.vb" Inherits="WebUI._Default" MasterPageFile="~/Site1.Master" %>
<!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>
</head>
<body>
<form id="form1" runat="server">
<div>
</div>
</form>
</body>
</html>
The master page:
<%@ Master Language="VB" AutoEventWireup="false" CodeBehind="Site1.master.vb" Inherits="WebUI.Site1" %>
<!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>
<asp:ContentPlaceHolder ID="head" runat="server">
</asp:ContentPlaceHolder>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:ContentPlaceHolder ID="ContentPlaceHolder1" runat="server">
</asp:ContentPlaceHolder>
</div>
</form>
</body>
</html>
Answer
Your web form shouldn't have all of that markup (like the <html> tag). Since it has a master page, you just start with the content tag. Your aspx page should look like this:
<%@ Page Language="vb" AutoEventWireup="false" CodeBehind="Default.aspx.vb" Inherits="WebUI._Default" MasterPageFile="~/Site1.Master" %>
<asp:content id="Content1" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
This is the body!
</asp:content>
When you're adding a new aspx page make sure to check "select master page" in the "add new item" dialog.