ASP.NET - How to get to Div control in ContentPlaceHolder?

Question

I've created very simple web site for the test purposes. Only one master page and one content page.

My content page looks like this:

<%@ Page Language="C#" MasterPageFile="~/MasterPage.master" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" Title="Untitled Page" %>

<asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
    <div id="TestDiv1">bla bla</div>
    <div id="TestDiv2">ble ble</div>
</asp:Content>

Now, based on some condition I would like to show/hide a given div. So I am trying to reach one of those divs by Controls collection, like this:

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
      ContentPlaceHolder myContent = (ContentPlaceHolder)this.Master.FindControl("ContentPlaceHolder1");
      myContent.FindControl("TestDiv1").Visible = false; //this is not working 
    }
}

    }
}

But the above example is not working. None of the two div control exists in the myContent.Controls collection. If I place for example a TextBox on my content page, I can reach it through Controls.

So what should I do to be able to access the div control?

Answer 1

your divs are HTMLcontrols, try to add them the tag runat="server"

<div id="TestDiv1" runat="server">bla bla</div>

That should solve your issue.

Answer 2

You need to set runat="server" on the divs.