How do you force Visual Studio to regenerate the .designer files for aspx/ascx files?

Sometimes when I’m editing page or control the .designer files stop being updated with the new controls I’m putting on the page. I’m not sure what’s causing this to happen, but I’m wondering if there’s any way of forcing Visual Studio to regenerate the .designer file. I’m using Visual Studio 2008

EDIT: Sorry I should have noted I’ve already tried:

  • Closing & re-opening all the files & Visual Studio
  • Making a change to a runat=”server” control on the page
  • Deleting & re-adding the page directive


Thank you for visiting the Q&A section on Magenaut. Please note that all the answers may not help you solve the issue immediately. So please treat them as advisements. If you found the post helpful (or not), leave a comment & I’ll get back to you as soon as possible.

Method 1

If you open the .aspx file and switch between design view and html view and
back it will prompt VS to check the controls and add any that are missing to
the designer file.

In VS2013-15 there is a Convert to Web Application command under the Project menu. Prior to VS2013 this option was available in the right-click context menu for as(c/p)x files. When this is done you should see that you now have a *.Designer.cs file available and your controls within the Design HTML will be available for your control.

PS: This should not be done in debug mode, as not everything is “recompiled” when debugging.

Some people have also reported success by (making a backup copy of your .designer.cs file and then) deleting the .designer.cs file. Re-create an empty file with the same name.

There are many comments to this answer that add tips on how best to re-create the designer.cs file.

Method 2

Well I found a solution that works, though I don’t really like it. I had to delete the .designer.cs file then recreate an empty file with the same name. When I went back in and saved the aspx file again, the designer file was re-generated.


Method 3

I use the following method which works everytime:

  • Select all of the code-in-front (html markup etc) in the editor of the aspx/ascx file.
  • Cut.
  • Save.
  • Paste.
  • Save.


Method 4

I recently saw that I was having the same problem. Visual Studio 2010 was refusing to update the designer file.

As it turns out, VS doesn’t modify the designer file for a page that uses CodeFile (run off of pages) instead of CodeBehind (DLL). This is true no matter how many times you close VS, reload the project, re-create the control(s), or modify a file. Nothing would prompt VS to regenerate the designer. It’s as if it doesn’t create the designer file for CodeFile pages but does require it to be there.

I changed it to CodeBehind and saved the page. The designer file updated immediately. Then I just changed it back and everything was still golden. This behavior seems to be new with VS 2010 / .NET 4.0 as VS 2008 by default didn’t suffer from this.

It’s this part:

<%@ Page Language="vb" AutoEventWireup="false" CodeFile="YourPage.aspx.vb" Inherits="YourPageClass" %>

Change CodeFile to CodeBehind, save, and then revert.

Method 5

There is another possibility: You may have an error in your .aspx file that does not allow Visual Studio to regenerate the designer.

If you switch to Design View, it will show the control as unable to be rendered. Fixing the control (in my case it was an extra quote in the properties) and recompiling should regenerate the designer.

Method 6

Most of the solutions here don’t work if you’re running Visual Studio 2013 and possibly 2012. Microsoft probably introduced some optimizations to make the IDE snappier, consequently they’ve reduced the number of cases that trigger the code generator. The following scenarios that used to work no longer do:

  1. Delete the aspx or ascx file — No longer checks for this case
  2. Cut all the content and repaste into the aspx or ascx file — No longer works, no change in the references
  3. Convert to Web Application — Option no longer available
  4. Arbitrarily changing content on the aspx/ascx file — No longer works (see 2).

The solution is surprisingly simple, but it’s slightly cumbersome. In order to trigger the code generator, change something that would require the designer.aspx.cs to be generated. Changing content that doesn’t affect code, such as a CSS style or adding text, won’t trigger the code generator. You must change a referenced control. Here’s how to do it:

In the ascx or aspx change the ID of the control

<asp:HyperLink ID="MyLink" runat="server" NavigateUrl="~/Default.aspx" Text="Home" />


<asp:HyperLink ID="theLINK" runat="server" NavigateUrl="~/Default.aspx" CssClass="tab" Text="Home" />

Go to the ascx.cs or aspx.cs and make sure you rename all references to “MyLink” to “theLINK” as well. Save and do build and the you should be good to go.

Method 7

the only way I know is to delete the designer file, and do a convert to web app. However when you do this, it usually pops up with the error, as to why it didn’t auto-regen in the first place, its usually a control ref that isn’t declared in the head of the page.

Method 8

Convert to Web Application did not work for me.

Deleting designer.cs and pasting a blank designer.cs did not work either.

But yes this worked:

  1. Select all(Default.aspx)
  2. Cut
  3. Save Default.aspx
  4. Paste
  5. Save Default.aspx

Done. New designer.cs generated. 🙂

Method 9

I often found that copy/pasting caused this behaviour for me. Most cases can be solved by editing the ID of a server control (just add a character, then delete it).

Also remember that control inside things like Repeaters aren’t visible in the designer file.

And yes, there are cases where you need to do the delete-the-file magic listed above – but the name-change solution will work most of the time.

Method 10

My experience is that if you want to do like in this article, like stated above.

Your markup file (aspx/ascx) has to include the CodeBehind=”MyPage.aspx.cs” attribute or else it won´t work. I blogged about it here.

Method 11

I’ve found a way to solve this problem without changing any code or running commands like “Convert to Web Application” – and it’s simple too!

What I found was that restarting Visual Studio often solves the problem, but sometimes it doesn’t. In those cases, if you close Visual Studio and then delete all content in the “obj” directory for the web project before you open it again, it has always worked for me.

(when started again you just add a space and remove it again and then hit save to have the designer file properly regenerated)

Method 12

(The following comes from experience with VS2005.)

If you edit an ASPX page while debugging, then the codebehind doesn’t get updated with the new classes. So, you have to stop debugging, trivially edit the ASPX page (like add a button or something), then click Design View, then delete the button. Then, your designer files should be updated.

If you are having a different issue with VS2008, then I can’t help.

Method 13

When you are in design view, right click on the screen and hit refresh.

Method 14

Another thing which worked was –

  1. Manually delete & then Create a designer file in filesystem.
  2. Edit Project file.
  3. Add code to include designer
    Eg: <Compile Include="<Path>FileName.ascx.designer.cs">
  4. Reload Project
  5. Open as(c/p)x file in design/view mode & save it.
  6. Check designer file. Code will be there.

Method 15

If you are using VS2013 or later , make sure that the code referenced with attribute “CodeBehind” not “CodeFile”, then do below steps

<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="yourControl.ascx.cs" Inherits="yourControl.yourControl" %>
  • create empty designer page (or clear it if it’s already exists “yourControl.ascx.designer.cs”)
  • in the ascx (or aspx) copy all code , the delete it, then save. re-past it again , then save.
  • the designer file should be populated now.

Method 16

  • Select-all in the designer file and delete everything in the file, leaving it blank and then save
  • Select-all in the ASPX/ASCX file and cut everything and then re-paste it back
  • The designer file should have regenerated the code

Method 17

Here is wat i experienced ,
Select the website folder right click in the Solution Explorer, select Convert to Web application for all the aspx file a designer file will get generated.


Method 18

Just to add to the long list of answers here – I’ve just run into this issue in VS2010 (SP1) with an .aspx file. I tried adding and removing standard ASP controls (which has worked in the past) but in the end, I had to remove one of the runat=server lines from an existing control (and save) to force the designer file to regenerate.

Method 19

The solution the worked for me is:

I just copied the page and and pasted it in the same portion, then renamed the first page(what ever name) and renamed the copied page as the original page. Now the controls are accessible.

Method 20

I’ve encountered the same problem for years now, working in Visual Studio 2008. And I’ve tried every “solution” on StackOverflow and dozens of blogs, just like I’m sure all of you have. And sometimes they work, and sometimes they don’t, just like I’m sure all of you have encountered. And apparently it’s still an issue in VS2010 and VS2012.

So finally, a couple of months ago, I decided enough was enough, and over a few weeks I built a tool called “Redesigner” that generates .designer files. It’s open-source under the BSD license, with the source code available on SourceForge — free to use, free to steal, free to do anything you please with. And it does what Visual Studio fails to do so often, which is generate .designer files quickly and reliably.

It’s a stand-alone command-line tool that parses .aspx and .ascx files, performs all the necessary reflection magic, and spits out correct .designer files. It does all the parsing and reflection itself to avoid relying on existing code, which we all know too well is broken. It’s written in C# against .NET 3.5, but it makes pains to avoid using even System.Web for anything other than type declarations, and it doesn’t use or rely on Visual Studio at all.

Redesigner can generate new .designer files; and it offers a –verbose option so that when things go wrong, you get far better error messages than “Exception of type System.Exception was thrown.” And there’s a –verify option that can be used to tell you when your existing .designer files are broken — missing controls, bad property declarations, unreadable by Visual Studio, or otherwise just plain borked.

We’ve been using it at my workplace to get us out of jams for the better part of the last month now, and while Redesigner is still a beta, it’s getting far enough along that it’s worth sharing its existence with the public. I soon intend to create a Visual Studio plugin for it so you can simply right-click to verify or regenerate designer files the way you always wished you could. But in the interim, the command-line usage is pretty easy and will save you a lot of headaches.

Anyway, go download a copy of Redesigner now and stop pulling out your hair. You won’t always need it, but when you do, you’ll be glad you have it!

Method 21

Edit the Inherits attribute of the ASPX page’s @Page directive and hit Save. Your designer file should be regenerated.

Ensure that Inherits = <namespace>.<class_name> and CodeBehind = <class_name>.aspx.cs

I was trying to do this on a Sharepoint 2010 project, using VS 2010 and TFS, and none of the solutions above worked for me. Primarily, the option, “Convert to Web Application” is missing from the right-click menu of the .ASPX file when using TFS in VS 2010.

This answer helped finally. My class looked like this:

namespace MyProjects.Finance.Pages
    public partial class FinanceSubmission : WebPartPage
        protected void Page_Load(object sender, EventArgs e)

        // more code

And my @Page directive was (line-breaks here for clarity):

<%@ Page Language="C#" AutoEventWireup="true" 
    MasterPageFile="~masterurl/default.master" %>

I first changed the Inherits to MyProjects.Finance.Pages, hit Save, then changed it back to MyProjects.Finance.Pages.FinanceSubmission and hit Save again. And wallah! The designer page was regenerated!

Hope this helps someone using TFS!

Method 22

Within the Visual Studio:

1) Remove your aspx.designer.cs file

2) Right click on your aspx file and select “Convert to Web Application”
This should add the aspx.designer.cs back and up to date.

If you get an error saying:

“Generation of designer file failed: The method or operation is not implemented.”

Try close Visual Studio and then reopen your project and do step number two again

How to generate aspx.designer.cs in visual studio?

Method 23

in solution explorer just right click and select convert to web application. It will generate all the designer files again.

Method 24

  1. Step 1: Select all your aspx code, Cut [ CTRL+X ] that code and Save.
  2. Step 2: Again paste the same code in the same page and save again

Now your .desinger page will refresh with all controls in .aspx page.

Method 25

Delete the designer.cs file and then right click on the .aspx file and choose “Convert To Web Application”. If there is a problem with your control declarations, such as a tag not being well-formed, you will get an error message and you will need to correct the malformed tag before visual studio can successfully re-generate your designer file.

In my case, at this point, I discovered that the problem was that I had declared a button control that that was not inside of a form tag with a runat=”server” attribute.

Method 26

This is a bug in the IDE; I’ve seen it since VS 2003. THe solution is simple though.

Save your files. Completely exit the IDE (make sure the process stops, task mgr.)

Reopen the solution, dirty the markup, save. Fixed.

Method 27

I had two problems… outdated AJAXControlkit – deleted the old dll, removed old controls from toolbox, downloaded new version, loaded toolbox, and dragged and dropped new controls on the page (see

Also had misspelling in my label control (had used ‘class’ instead of ‘cssclass’).


Method 28

I had the problem that my new controls would not generate in the designer file when declared in the .ascx file. The problem was that i declared them in the code behind also. So deleting the declaration in the code behind solved my problem.

Method 29

If you are like me and you add old .ASPX files to a more recent project.
You are probably going to forget some of the controls used on the page.

If so, first thing, if there are multiple files you are installing;
Fix one at a time first.

When you compile, fix errors generated. They will probably be the same
errors in all the files.

Next, if you have Designer files, delete all of the inserted – designer files.
Next, make sure there are not any other errors when you compile, other than
the designer files.

Finally right click your web project and click on Convert to Web Application.
This will insert the designer files you need.

These are the absolute best steps to fix the issues.

Method 30

One thing that nobody’s mentioned is to visit the page. I had my designer file stop regenerating because I was including a user control that didn’t exist (for various reasons), and none of the things suggested here worked. For whatever reason, I didn’t get any errors in Visual Studio – besides the one complaining about the fact that my client-side controls didn’t exist because they weren’t being regenerated, of course.

It took actually visiting the page to get ASP.Net to tell me the error.

All methods was sourced from or, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0

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