CODEWITHSUNDEEP
asp.netinclude
Hank Knah
Hank Knah

Reputation: 101

How to avoid build errors with aspx include files?

I have an aspx file that will contain a lot of sections and I would prefer to have each section in its own include file. I'm okay to put all of the code behind into the main file. I'm using: <!-- #include file ="section1.aspx" --> in the body. When I build (I'm still only including the first section with code), I get "The name 'lbl_phone' does not exist in the current context" because the code behind has a routine that references this screen field which IS in the include file. What is a better way to go about this?

Edit (as it is now, hope I cut it down properly here, builds good now but error in browser):

file ola.aspx

<%@ Page Language="C#" AutoEventWireup="true" Inherits="_ola" Codebehind="ola.aspx.cs" %>
<%@ Register TagPrefix="section" TagName="account" Src="account.ascx" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html><body><form id="ola_form1" runat="server">
<section:account id="section_account" runat="server" />
</form></body></html>

file: ola.aspx.cs

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Text.RegularExpressions;
using System.Data.SqlClient;
    public partial class _ola : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
    {
        lbl_phone.Text = "000-000-1234";
    }
}

file: account.ascx

<%@ Control Language="C#" ClassName="_ola" CodeBehind="account.ascx.cs" %>
Call us at <asp:Label ID="lbl_phone" runat="server" Text="lbl_phone"></asp:Label>

At runtime in the browser, I get: Object reference not set to an instance of an object. (for the line with lbl_phone.Text = ...)

Upvotes: 2

Views: 629

Answers (2)

mason
mason

Reputation: 32728

Controls defined as part of a Page or Master Page or User Control are private by default. To get around that, add a public property that exposes it. Put this property in account.ascx.cs

public Label lbl_phone_public_version{ 
    get {
        return lbl_phone;
    } 
}

When you try to reference lbl_phone from code on ola.aspxcs, you have to do it through the parent control, like this:

    protected void Page_Load(object sender, EventArgs e)
{
    section_account.lbl_phone_public_version.Text = "000-000-1234";
}

Upvotes: 0

mason
mason

Reputation: 32728

Don't use server side includes. They don't work well in the ASP.NET architecture.

Instead, embed reusable stuff into .ASCX user controls. MSDN How To article.

ASCX File MyControl.ascx

<% @ Control Language="C#" ClassName="Spinner" %>  
<table>
<tr><th>Column 1</th><th>Column 2</th></tr>
<tr><td>Some content</td><td>Some more content</td></tr>
</table>

Then this can be embedded on as many ASPX pages as you like.

<%@ Register TagPrefix="uc" TagName="MyControlName" Src="~\Controls\MyControl.ascx" %>
<uc:MyControlName ID="MyControl1" runat="server" />

Edit- You should make these ASCX files as portable as possible in your application so that they're self contained units. There shouldn't be much of a need for your ASPX code behind to reference a control contained in the ASCX file. You can do code behinds for user controls (MyControl.ascx.cs or MyControl.ascx.vb) if necessary, or you can use a script block to embed the code directly in the ASCX page.

.NET Framework will not follow server side includes and so it won't compile properly if you try to reference a control that is being included via SSI. But you could potentially reference a control in an ASCX file. For example...

MyAdvancedControl.ascx

<% @ Control Language="C#" ClassName="Spinner" %>  
<asp:Label runat="server" id="lbl_phone" />
<script runat="server">
public Label Lbl_phone {get {return lbl_phone;}}
</script>

MyPage.aspx

<%@ Register TagPrefix="uc" TagName="MyAdvancedControlName" Src="~\Controls\MyAdvancedControl.ascx" %>
<uc:MyAdvancedControlName ID="MyControl2" runat="server" />

MyPage.aspx.cs

protected void Page_Load(object sender, EventArgs e)
{
    MyControl2.Lbl_phone.Text="Galaxy S4";
}

Upvotes: 1

Related Questions