What am I doing wrong in ASP.NET

Question

Here is my master page code behind:

namespace mysite.MasterPages
{
    public partial class Main : System.Web.UI.MasterPage
    {
        public bool isLoggedIn;

        protected void Page_Load(object sender, EventArgs e)
        {
            isLoggedIn = Request.IsAuthenticated;      // Is the user currently logged in
        }
    }
}

Here is my register page code behind:

namespace mysite
{
    public partial class _Default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (((MasterPage)Page.Master).isLoggedIn)
            {
                Response.Redirect("default.aspx");
            }
        }
    }
}

I'm trying to make the isloggedIn accessible to all pages using that as a master page! I get errors like:

Error 2 The name 'isLoggedIn' does not exist in the current context

Error 3 'System.Web.UI.MasterPage' does not contain a definition for 'isLoggedIn' and no extension method 'isLoggedIn' accepting a first argument of type 'System.Web.UI.MasterPage' could be found (are you missing a using directive or an assembly reference?)

Any help appreciated.

Answer 1

Usually one would store such Global 'states' inside a session variable. Are passing it around as a query string parameter?

And why are you not putting the code in the code behind?

Edit 1:

Just move this logic:

  Response.Redirect("default.aspx");

directly into your masterpage:

 protected void Page_Load(object sender, EventArgs e)
    {
        if (Request.IsAuthenticated)      // Is the user currently logged in
        {
            Response.Redirect("default.aspx");
        }
    }

If this is the default behaviour you want for all pages that will be using this Master Page.

Edit 2:

you said in a comment :

and how would i go about accessing the variable on other pages?

There are 3 ways I can think of:

• Query String (Per Page Request)
• ViewState (Per Page)
• Session Variable (Available Globally)

Answer 2

The problem here is that your are declaring isLoggedIn within an inline code-block, so it will only be scoped to within that block.

You'll need to add it as a variable within the code-behind class or within <script runat="server"></script> tags, if adding the server-side code inline, i.e. (trimmed down for brevity):

<script runat="server">

    public bool IsLoggedIn;

    protected void Page_Load(object sender, EventArgs e)
    {
        IsLoggedIn = Request.IsAuthenticated;
    }

</script>

You could then access the master page in subpages like so:

<%
    if (((MasterPage)Page.Master).IsLoggedIn)
    {
    }
%>

However, I'm not sure that this is the best way to achieve what you want. I would probably take that logic out of the master page and stick it in a purpose built authentication class or service.

Answer 3

add <%@ MasterType VirtualPath="~/Main.master" %> to your page markup.

and your this.Master's type becomes AlphaPack.MasterPages.Main instead of System.Web.UI.MasterPage. So you will be able to access it without cast:

 this.Master.IsLoggednIn

Currently you need do next:

((AlphaPack.MasterPages.Main)this.Master).isLoggednIn

And better - create a property. And hold data not in variable but in ViewState (read Control State vs. View State):

namespace AlphaPack.MasterPages
{
    public partial class Main : System.Web.UI.MasterPage
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            this.IsLoggedIn = Request.IsAuthenticated;
        }

        public bool IsLoggedIn
        {
            get { return this.ViewState["isLoggedIn"] as bool? ?? false; }
            set { this.ViewState["isLoggedIn"] = value; }
        }
    }
}

And what about code-behind. I recommend to use Web App project, not Web Site project (which is out-of-date)!

Next markup syntax is used. Web app:

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="MyPage.aspx.cs" Inherits="MyNamespace.MyPage" MasterPageFile="~/MyMaster.master" Title="MyTitile" %>

and web site:

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="MyPage.aspx.cs" Inherits="MyPage" MasterPageFile="~/MyMaster.master" Title="MyTitile" %>

Answer 4

if (((MasterPage)Page.Master).isLoggedIn)

Should be

if (((mysite.MasterPages.Main)Page.Master).isLoggedIn)

You cast Master to a MasterPage type (which is useless as it is already a MasterPage). But MasterPage doesn't contain the property isLoggedIn. That's why you can't access it.

So, just cast the Master property to the right type, in your case mysite.MasterPages.Main