VB.NET UserControl For .NET: "not A Known Element"?
Mar 25, 2011
I've created a UserControl in VB.NET and added it to a form. But it looks like I've done it wrong as it is underlined with the message:
ctlDropDown is not a known element. This can occur if there is a compilation error in the Web site or the web.config file is missing.When I try to run it I get the following error: myControl is not allowed here because it does not extend class System.Web.UI.UserControl.
Here's the code:
control itself...
<%@ Control Language="vb" AutoEventWireup="false" CodeBehind="ctlDropDown.ascx.vb" Inherits="myProj.UserControls.ctlDropDown" TargetSchema="http://schemas.microsoft.com/intellisense/ie5" %>[code].....
I created (vs2008 C#) an "asp.net web server control" project. I then remove the default .cs and replace it with an "asp.net web server control" cs file which has a default name of WebCustomControl1.cs. I named the project CCContainer and renamed the .cs file as CCContainerA.cs, so the class name is CCContainerA. I then create a new (VS2008 C#) web application in which I add my custom control. After compiling CCContainer to CCContainerA.dll I create a reference to this dll in the web app, and add CCContainerA.dll to my web app's toolbox. When I drag my custom control to the webform I automaticall get this directive line:
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?
This doesn't happen when I create the site in my local drive. Is there a workaround to this. Even if I add the missing parts, I keep getting the same error.
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<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server"> <asp:Content --- showed a green wavy line , and on hover displayed the above error.
Now I am having certain problems.
1. Visual Studio 2010 hangs when I try to use ToolBox.
2. Intellisense for asp.net controls is not working.
I have tried replacing web.config file (frm backup) , tried to debug - it doesnt show anything.
All other websites are working alright. Have problem with only one of the websites.
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I got this errors while trying to use an example from the ASP.NET 3.5 Unleashed book.
Webform1.aspx
[Code]....
LengthValidator.cs
[Code]....
As from the book's note, I think I added this line correctly:
[Code]....
However, the compiler kept complaining that:
Warning 1 Element 'LengthValidator' is not a known element. This can occur if there is a compilation error in the Web site, or the web.config file is missing. C:Visual Studio 2010 ASP.NET ProjectsWebApplicationFourWebApplicationFourWebForm1.aspx 16 17 WebApplicationFour
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My app is working properly but visual studio showing warning like that.
I've a ASP.Net page (Default.aspx) which will load UserControl (ucontrol.ascx) dynamically into an UpdatePanel. By using UpdatePanel, we believe we're able to prevent the entire page to be posted-back.
My problem is, within the UserControl, we have some form controls, such as inputs and buttons; after the UserControl is loaded, clicking on any button inside the UserControl will cause the UpdatePanel to be blanked. During the investigation, I found that, breakpoints within the Button1_Click() in the code-behind for the UserControl is never reached. Please reference to the code below, this references to [REFERENCE]1.
I have a page with an UpdatePanel with a UserControl in it. That UserControl contains a GridView with a nested UserControl that seems to disappear when the parent UserControl is rebound. I cannot for the life of me figure out why the child UserControl disappears. The code works beautifully on the first load, but any partial postback causes the "Pick" UserControl to disappear.
im creating site with usercontrols. I have repeater, inside it is another repeater with usercontrol. My problem is passing BindedValue to usercontrol.Bindings works fine and binds the value i need but it cannot pass the value to usercontrol. When i type it manually it works, when i bind it, it passes null (!).I've tried get,set, functions (ondatabound, onload, oninit), accessing control from code with no luck. Ive read and tried to do all the google solutions but with no luck. (even with creating usercontrol inheritance)
There are 2 UserControls UC1 and UC2, and there is one more class C. I want to share the same instance of c in both UserControls. I know that this can be possible with properties in both UC's and by registering UC2 in UC1 or vice versa. But I want the solution to be loosely coupled. Any best possible way without touching the Actual Page (which hosts UC's)? So i need some best possible way between UCs transfering C.
I have a UserControl, which contains another UserControl with Button. I want to add an event to that button in first UserControl (parent). I tried to do:
void Page_Init() { var btn = ChildControl.FindControl("SearchButton") as Button; btn.Click += new EventHandler(this.SearchButton_Click); }
Here I have gridview control with checkbox for selection of one or two records. Have one button and when clicking this , i need to get the selected records values and assign this values to the textbox which is in usercontrol1.
I converted a forms website into an application and everything has been working just fine until now. I keep getting the green squiggly lines and the error that Element 'X' is not a known element. This is on almost every element, Gridview, Label, Update Panel, Hyperlink Field, Bound Field, etc...
so ajax and asp are viable prefixes. The very odd thing is that it is only happening on a few user controls, all other user controls are fine and the errors never show up. I have tried rebooting and everything and nothing seems to fix it. All masterpages, web paages, and about 90% of the user controls are fine, its only on a few user controls and super annoying!
