Home/ Questions/Q 7603885
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-30T23:45:59+00:00

I have an asp.net web page. The code: <%@ Page Language=C# AutoEventWireup=true CodeBehind=Login.aspx.cs Inherits=Works.Login

  • 0

I have an asp.net web page. The code:

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Login.aspx.cs" Inherits="Works.Login" %>
<!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>
      <link rel="stylesheet" type="text/css" href="/styles/source/style.css" />
   </head>
   <body id="PageBody" runat="server">
      <form id="form1" runat="server">
         <div style="text-align: center" >

And in code behind I want to add something to the body attribute.

protected void Page_PreRender(object sender, EventArgs e) 
{ 
        if (PageBody != null) 
        { 
            PageBody.Attributes.Add("class", "some_image");

However I found it doesn’t work at all. I stepped through into the code and found there is an exception.

InnerText = ‘((System.Web.UI.HtmlControls.HtmlContainerControl)(((System.Web.UI.HtmlControls.HtmlGenericControl)(PageBody)))).InnerText’
threw an exception of type ‘System.Web.HttpException’}

Thanks for your help.

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    Do in the PageLoad, It works.

       protected void Page_Load(object sender, EventArgs e)
    {
        if (PageBody != null)
        {
             PageBody.Attributes.Add("class", "myClass");
        }
    }

    EDIT : Full code to show this is working (since the op is doubtfull abt it)

    My ASPX page

    <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm4.aspx.cs" Inherits="SO.WebForm4" %>
<!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>
    <style>
    body
    {
        background-color:Olive;
    }    
    .myClass
    {
        background-color:Orange;

    }
    </style>

</head>
<body id="PageBody" runat="server">
    <form id="form1" runat="server">
    <div>
      <h2>Testing styles</h2>
       <p>If the bg color is Orange, code is working</p>
    </div>
    </form>
</body>
</html>

    Codebehind

    using System;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace SO
{
    public partial class WebForm4 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (PageBody != null)
            {
                PageBody.Attributes.Add("class", "myClass");
            }
        }
    }
}

    and here is the output

    enter image description here

    • 0