Access a content page variable through the master page

asp.net, master-pages

Solution

Yes you can. You have to implement a base class and content class should be derived from that base class.

EDIT : Posted markup and changed code for a clearer example

I have created a base page inherited the System.Web.UI.Page, then made the content page inherit it. My basepage:

namespace WebApplication2
{
    public class BasePage : System.Web.UI.Page
    {
        public BasePage() { }

        public virtual string TextValue()
        {
            return "";
        }

    }
}

Here's my content page markup:

<%@ Page Title="Home Page" Language="C#" MasterPageFile="~/Site.Master" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="WebApplication2._Default" %>


<asp:Content runat="server" ID="BodyContent" ContentPlaceHolderID="MainContent">
    <asp:Label ID="lblContentText" Text="Contentpage TextValue:" runat="server"></asp:Label>
    <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
</asp:Content>

Content page code:

namespace WebApplication2
{
    public partial class _Default : BasePage
    {
        protected void Page_Load(object sender, EventArgs e)
        {

        }

        public override string TextValue()
        {
            return TextBox1.Text;
        }
    }
}

My Masterpage markup:

<%@ Master Language="C#" AutoEventWireup="true" CodeBehind="Site.master.cs" Inherits="WebApplication2.SiteMaster" %>

<!DOCTYPE html>
<html lang="en">
<head runat="server">
    <meta charset="utf-8" />
    <title><%: Page.Title %> - My ASP.NET Application</title>  
    <asp:ContentPlaceHolder runat="server" ID="HeadContent" />
</head>
<body>
    <form runat="server">    
    <header> </header>
    <div id="body">
        <asp:Label ID="lblText" runat ="server" Text="Masterpage Text :" />
        <asp:TextBox ID="txtMaster" runat="server"></asp:TextBox>
        <asp:Button ID="Button1" runat="server" Text="Click to read content page TextValue " OnClick="Button1_Click" />
        <asp:ContentPlaceHolder runat="server" ID="MainContent" />
    </div>
    <footer>
    </footer>
    </form>
</body>
</html>

And the implementation in masterpage code behind:

namespace WebApplication2
{
    public partial class SiteMaster : MasterPage
    {
        BasePage Currentpage = null;
        protected void Page_Load(object sender, EventArgs e)
        {

        }

        protected void Button1_Click(object sender, EventArgs e)
        {
            Currentpage = this.Page as BasePage;
            if (Currentpage != null)
            {
                txtMaster.Text = Currentpage.TextValue();
            }
        }
    }
}

If you see any error like BasePase is not recognized, Please make sure that either it is using same namespace(i.e. WebApplication2), or the namespace is added to the implementation page (i.e. using WebApplication2;).

Hope it helps!

Problem

I know in ASP.net, we can access a master page variable through content page, but is there anyway we can access a content page variable through the master page?

Original source