Adding meta tag dynamically to aspx pages

Question

4.00/5 (1 vote)

See more:

HI,

I inspired from codeproject article " Using metatag with master pages in asp.net"

I created a web site. Which has two master pages. 1-Main Master Page, 2- Nested master page for the Main Master
page.
I got different aspx files in my page folder. some of these pages derived from nested master Page and some from
directly Main master page.

In my main master page(i.e sitemaster1) in the head section i have many links to Css files and Jquery files and
javascript files.
you can have look below to my main master page. i'm just putting here my code up to header section only.( where i'm
facing problem).

<%@ Master Language="C#" AutoEventWireup="true" CodeFile="siteMaster1.master.cs" Inherits="siteMaster1" %>
<!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">
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
<title>RRS</title>
<link href="Gcss/default.css" rel="stylesheet" type="text/css" media="screen" />
<link href="Gcss/menuStyles.css" rel="stylesheet" type="text/css" media="screen" />
<!-- slider tags -->
    <link rel="stylesheet" href="<%=ResolveClientUrl("~/Css/style.css") %>" type="text/css" media="screen"
charset="utf-8" />
    <script type="text/javascript" src="<%=ResolveClientUrl("~/js/jquery-1.2.6.js")%>"></script>
    <script type="text/javascript" src="<%=ResolveClientUrl("~/js/startstop-slider.js")%>"></script>
    <asp:ContentPlaceHolder id="head" runat="server">
    </asp:ContentPlaceHolder>

    <style type="text/css">
        #Password1
        {
            width: 113px;
        }
    </style>

</head>

Then after

I created a  basepage class in my App_code folder.  In which I have the following code.

private string _keywords;
    private string _description;
    public BasePage()
    {
        //
        // TODO: Add constructor logic here
        //
        Init += new EventHandler(BasePage_Init);
    }
    void BasePage_Init(object sender, EventArgs e)
    {
    if(!string.IsNullOrEmpty(Meta_Keywords))
    {
        HtmlMeta key= new HtmlMeta();
        key.Name="keywords";
        key.Content=Meta_Keywords;
        Header.Controls.Add(key);
    }
    if (!string.IsNullOrEmpty(Meta_Description))
    {
        HtmlMeta des = new HtmlMeta();
        des.Name = "description";
        des.Content = Meta_Description;
        Header.Controls.Add(des);
    }
    }
    public string Meta_Keywords
    {
        get
        {
            return _keywords;
        }
        set
        {
            _keywords = Regex.Replace(value, "\\s+", "");
        }
    }
    public string Meta_Description
    {
        get
        {
            return _description;
        }
        set
        {
            _description = Regex.Replace(value, "\\s+", "");
        }
    }
Then after My home page which is drived from Nested Master Page.
for my home page the code is like below.
home.aspx.cs  code here..
public partial class Home : BasePage
{
    protected void Page_Load(object sender, EventArgs e)
    {
    }
}

And
Home.aspx code here.

<%@ Page Language="C#" MasterPageFile="~/NestedMP1.master" AutoEventWireup="true" CodeFile="Home.aspx.cs"
Inherits="Home" Title="Home" CodeFileBaseClass="BasePage"
Meta_Keywords="Rapid, guarding"
 Meta_Description="Security Services from Rapid Response Security Services, Auckland"
 Meta_Author="kingsland and mt eden rapid response security ltd"

 %>

Ok Now the problem goes here.

When I run my HOme page I get the following error:

The Controls collection cannot be modified because the control contains code blocks (i.e. <% ... %>).
Description: An unhandled exception occurred during the execution of the current web request. Please review the
stack trace for more information about the error and where it originated in the code.
Exception Details: System.Web.HttpException: The Controls collection cannot be modified because the control
contains code blocks (i.e. <% ... %>).
Source Error:
The source code that generated this unhandled exception can only be shown when compiled in debug mode. To enable
this, please follow one of the below steps, then request the URL:
1. Add a "Debug=true" directive at the top of the file that generated the error. Example:
  <%@ Page Language="C#" Debug="true" %>
or:
2) Add the following section to the configuration file of your application:
<configuration>
   <system.web>
       <compilation debug="true"/>
   </system.web>
</configuration>
Note that this second technique will cause all files within a given application to be compiled in debug mode. The
first technique will cause only that particular file to be compiled in debug mode.
Important: Running applications in debug mode does incur a memory/performance overhead. You should make sure that
an application has debugging disabled before deploying into production scenario.
Stack Trace:
[HttpException (0x80004005): The Controls collection cannot be modified because the control contains code blocks
(i.e. <% ... %>).]
   System.Web.UI.ControlCollection.Add(Control child) +8678903
   BasePage.BasePage_Init(Object sender, EventArgs e) +111
   System.Web.UI.Control.OnInit(EventArgs e) +99
   System.Web.UI.Page.OnInit(EventArgs e) +12
   System.Web.UI.Control.InitRecursive(Control namingContainer) +333
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean
includeStagesAfterAsyncPoint) +378

Version Information: Microsoft .NET Framework Version:2.0.50727.4927; ASP.NET Version:2.0.50727.4927

Please help to write more easy to write meta tags in my aspx code. I'm really worried about this since 2 days.
Please solve me this problem.

Thank you.
IRFAN.

Posted 11-Mar-11 12:50pm

khanzzirfan

Updated 11-Mar-11 12:54pm

thatraja

v2

Add a Solution

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Albin Abel · Answer 1 · 2011-03-11T19:53:00

in your tags

VB

Meta_Keywords="Rapid, guarding"
 Meta_Description="Security Services from Rapid Response Security Services, Auckland"
 Meta_Author="kingsland and mt eden rapid response security ltd"

I think it is not Meta_Keywords It might be MetaKeywords. Same way remove that underscore for Meta_Decription as well. Take out the whole Meta_Author tag.

And you haven's mentioned which version your .Net framework

Improved Answer
----------------

In that case you need to remove the code blocks and add those links from code behind in the main master's page load event.

Need to give an id for the head section as <head runat="server" ID="HeadContent"> . Then in the master's page load use this code.

Use this namespace as well
using System.Web.UI.HtmlControls;

C#

HtmlLink CSSHtmlLink = new HtmlLink();
CSSHtmlLink.Attributes.Add("rel", "Stylesheet");
CSSHtmlLink.Attributes.Add("type", "text/css");
CSSHtmlLink.Attributes.Add("media", "all");
CSSHtmlLink.Attributes.Add("href", ResolveUrl("~/Styles/site.css"));
this.HeadContent.Controls.Add(CSSHtmlLink);


ScriptManager.RegisterClientScriptInclude(this.Page,this.GetType(),"script1", ResolveUrl("~/js/jquery-1.2.6.js"));
ScriptManager.RegisterClientScriptInclude(this.Page, this.GetType(), "script2", ResolveUrl("~/js/startstop-slider.js"));

khanzzirfan · Answer 2 · 2011-03-12T01:22:00

Solution 3

and I'm using .Net 3.5 version ...visual studio 2008 pro.

Posted 12-Mar-11 1:22am