Web Forms :: Can't Reference An Html Element From Code Behind In A User Control
Feb 2, 2010
Here is the contents of my test.ascx file:
<%@ Control Language="C#" AutoEventWireup="true" CodeFile="test.ascx.cs" Inherits="UserControls_test" %>
<p id="XXX">aaa</p>
and here is the contents of my test.ascx.cs file:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class UserControls_test : System.Web.UI.UserControl
{
protected void Page_Load(object sender, EventArgs e)
{
this.XXX.InnerHtml = "BBB";
}
}
I get an error when I refer to the id, "XXX" (underlined above) in code behind which reads: 'UserControls_test' does not contain a definition for 'XXX' and no extension method 'XXX' accepting a first argument of type 'UserControls_test' could be found (are you missing a using directive or an assembly reference?)
I have tried XXX.InnerHtml and I have tried this.XXX.InnerHtml and get same problem.
How do I successfully refer to ID'ed HTML elements in code behind?
But the problem is, I create the ID dynamically and I have multiple tables with IDs like "table1","table2", and so on....
string idFromDB = ... // retrieve the number from the database string fullId = "table" + idFromDB; HtmlTable tbl = .... get the element based on fullId .... ?????? tbl.Rows.Add( ... );
I have a user control which has html elements like <input type="button".... and i want to set its display property on preRender state.Would you please explain, what kind things i have to handle this user control? So, in this functionprotected override void OnPreRender(EventArgs e) { } I have only EventArgs e and it doesn't have proper method or properties to bring me the html of user control.
I have a <div> element in a web page. I've assigned it an "ID" and made it a server-side control by using "runat=server". How do I define that <div> in the code-behind. I'm been looking at the "System.Web.UI.HtmlControls" namespace and not sure what to use. The reason I need to do this is because within this <div> is a "Submit" button which will cause a postback. When I click the submit button the first thing it does is it executes a procedure to perform edit checks on the various textbox controls. If a control is empty, a message pops up. When the user clicks "Ok" for the message, the <div> disappears because when the form loads, the <div> style.display property is set to "none" by default. Basically, all I want is for the <div> not to disappear when the edit checks are performed and a messagebox pops up.
Now that I put this html inside a Tab containe (subpanel) the Page.Request.Form["Name"].ToString() fail, actually while I was debugging I could not find this element inside Page.Request.Form.
maybe there is another way of accessing the Html element from my c# code?
and it's not recognising that I added the span to the page. Is there something I need to do to make this happen? I have been working in MVC lately, so I haven't had to worry about the relationship between the page & code-behind in a while, but I can't remember any tricks that I had to perform to reference a HTML element in my code.
I'm trying to set a value for an HTML Element within my code-behind. I need to set a <div> elements "display" property to "inline". The way I have it coded is like this:
Code: divContact.Style("display") = "inline"
Is this the right syntax? I only ask because it doesn't seem to work but I don't get a run-time error when the statement is executes. ???
I've been hired to clean up a website that was written by another company. One of the main issues they have is that the navigation menu doesn't always match the content. On closer look, they didn't use a navigation control or an accordion, but made their own user control out of HTML UL's and LI's (see below). Each section is supposed to expand when you click on it to offer sub menus. Any how, I am trying to find a way when the content pages load to force the menu to focus on the correct UL. Any thoughts on how to do this? By the way they wrote this stuff in 2.0, which I guess maybe why they didn't use the Accordion from the AJAX Toolkit.
HTML Code: <div class="left-menu"> <div class="arrowlistmenu"> <h3 id="H3mymessage" class="menuheader expandable" onclick="RedirectBrowser(1)"> My Messages </h3>
[Code] ....
Redirect Browser is defined on the master page:
HTML Code: <script type="text/javascript"> function RedirectBrowser(ID) { if (ID == 1) window.location="MyMessageList.aspx?MessageFolderID=-1"; else if (ID == 2)
[Code] ....
Here is an example of how it is messed up. My Messages should be highlighted but My Profile is.
I'm looking at an asp.net application, i notice that there are assemblies defined into two places. In web.config there is configuration/system.web/compilation/assemblies/add elements. In the project file there are references setup under the Project/ItemGroup/Reference elements.
I was wondering, what is the difference between assemblies/references added in either location?
I am trying to assign user control from another user control ..first time its binding control successfully but when we refresh the data its giving error
saying "Object reference is not set an instance".
how to refresh data from another user control ...
My senerio below :
1 Aspx page
2. User control
calling usercontrol databinding method from aspx page but once it get refreshed ,not allowed to bind it again..
I am struggling with something that I guess should be standard practice really. I have a number of user controls that use some JQuery plugins. I do not really want to link to the extra CSS and JS files from my main masterpage as this would cause extra load to the user the first time they hit the site, (admittedly it would only be the once), so I was just putting them links into the top of the user control. Then I looked at my source HTML, not nice! Even worse for controls that repeat multiple times on a page.
So I was thinking is there a way of injecting them into the Head of the page when they are needed from the User Control. For that matter is there a way of doing it to the footer for JS stuff?
My observation so far in the output rendered by a datalist (when I use this user control inside it) is that the value for the name attribute is the same.I want to use this control inside a datalist/repeater such that I'd want a unique value for the input element's name attribute when the datalist/repeater renders. How is this done?
EDIT: My bad obversation. Actually the names are unique. However, when I try to post the page to another web page which outputs the key & value of all the items in Request.Form I don't see the input elements...
public class CustCtl : WebControl { protected override System.Web.UI.HtmlTextWriterTag TagKey { get { return HtmlTextWriterTag.Div; } } }
With this bare bones control, it would render the root element as a Div tag. But how can I add attributes to that root HTML element that this control will render .
I'm getting an "Object Reference Not Set to an Instance Of An Object Error" in a Web User Control that I've created when referencing any control in the Code Behind. Intellisense reports that the control exists in the aspx, but whenever I build and run I get that error.
Two separate questions, but sufficiently intertwined that I'm going to try the two together....
Firstly - User Controls and Behaviours
I have a User Control which contains a few visual controls. I am attaching some behaviours by using GetScriptDescriptors and am passing some JavaScript to the browser using GetScriptReferences. That is all rock solid and working well. However, when developing, I did discover that I couldn't attach the ehaviours to the User Control itself - not surprising as rendering a User Control does not create a DOM element which represents the actual control. So, I have attached my behaviours to a "random" TextBox within the User Control.
So - first question, is there a better way to do that? For example, should I always be rendering a SPAN as an element to surround the control? Not sure what that would do to the robustness of the rendering. What is the right way to attach a behaviour to a User Control.
Secondly - Accessing those same Behaviours later
Assume I have placed a User Control on the page. That User Control exposes a Property (actually a Javascript Function of course) which does "something" to the control - for the sake of example we'll say that the function is set_Border(colour). I then have a behaviour on the same page (actually an Extender on a different control) which needs to call the function. I have a reference to the User Control in my script, so I have tried TheControlReference.set_Border('red') and find that my control doesn't support the set_Border method.
I guess this is probably because the behaviours are not attached to the User Control itself, but to a GUI element within it. Hence, I suspect that the answer to the second question lies within the answer to the first.
i am trying to enter a value into a texbox that is placed inside a user control called CollectionRequest. i have referenced this user control in my code behind and created an instance of it but i seem to get the above error when i try to enter some manual text. code as follows:
protected CollectionRequest collReq; protected void Page_Load( object sender, EventArgs e ) { collReq = (CollectionRequest)LoadControl("~/CollectionRequest.ascx"); TextBox _txt_address = (TextBox)collReq.FindControl("txt_Address"); _txt_address.Text = "thisi is an address"; control has been referenced in source file <%@ Reference Control="~/CollectionRequest.ascx"%>
i am caling this code in my Approval.ascx.cs code. both the user controls are displayed together in the default.aspx page one above the other.
I am stuck into a problem, i have a user control ProductListing.ascx that contains ListView binded to an object datasource, SelectMethod and SelectCountmethod are provided as well. Everything works fine but the problem started when i add another user control declarativlly Filter.ascx in the productListing.ascx. I want to assign value to a public property MaxPrice in Filter.ascx. I am trying to set this property in the SelectMethod of ObjectDataSource. Usercontrol "Filter.ascx" throws null reference exception when i try to set its MaxPrice Property.
I tried to acced the usercontrol in Databind method of ListView , it is accessible here but viewstate is empty at this point, i saved the value in viewstate in SelectMethod of objectDatasource but i cant access viewstate in ListView Databind. Its empty. Its a simple code and no rewriting to viewstate elsewhere.
Important: My Codebehind files are in a seperate project and .ascx files in seperate project
I have an ASP.NET 4.0 application with some simple user controls. The user controls work fine on the design surface (VS.NET 2010), but when they're loaded during application execution, nothing shows up.
Futhermore, the various child controls of the user controls are null when referenced inside the code behind for the user control.
The code behind for the user control executes as expected, but any reference to child controls are null.
It's like ASP.NET is never parsing the ASCX to create the instances of the child controls.
I have created a web user control. It contains a table that has several image buttons. I want them to behave link a tab control. Here's the souce view:
I am using ckeditor as my Rich Text Editor (RTE). This is an html element control and not an ASP control. I would like to use the RequiredFieldValidator (RFV) control to make this field required.
I cannot find any documentation stating that the RFV can be used like this. Can anybody tell me if this is possible?
Here's an example - notice that there is an html textarea element - how do I use RFV on this?
