Hi I saw the video in link: http://www.asp.net/web-forms/videos/how-do-i/5-minute-introduction-to-aspnet-web-forms is a great example, but when I applied it using VS 2012 Ultimate... when open the project some pages shows no information but the masterpage template layout, everything seems fine in VS but the preview shows nothing
In some pages  I created
1 Entity data source
2 GridView
3 DetailsView...
Browser does not show them, just show the master page elements
Here is the code of one of the pages that seems fine in VS but when I preview them the GridView and DetailsView are not there...
Please your help.
LZ
<%@ Page Title="" Language="C#" MasterPageFile="~/Site.Master" AutoEventWireup="true" CodeBehind="CrearUsuarios.aspx.cs& ...

Go to the complete details ...