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

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.

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.

Dodgy!

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.

Recompile.

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.

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.

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.

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.

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.

(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.

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"> <DependentUpon>FileName.ascx</DependentUpon> </Compile>
4. Reload Project
5. Open as(c/p)x file in design/view mode & save it.
6. Check designer file. Code will be there.

• 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

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.

Sameer

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.

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.

The solution was for me to change from None to Compile in .csproj file

<Compile Include="Logout.aspx.designer.cs">
      <DependentUpon>Logout.aspx</DependentUpon>
</Compile>

1. replace your custom tag with a invalid tag name. Save it
2. restore the invalid tag name back to custom tag name. Save it. Then you will be prompted to checkout the *.designer.cs files(or silently modify the designer.cs) and produce correct variable of custom tag control.

I had this problem and for me, I had a space in one of my ID values for one of my controls. I took the space out and the designer file regenerated itself.

1. Close designer.cs.

2. Change your aspx file to design view.

3. Right-Click –> Refresh.

4. Save

One of my solution, which works for me.

1. Close the Visual Studio
2. Remove hidden .vs directory
3. Remove existing .sln file
4. load the project in visual studio using .csproj file

In Visual Studio 2019 below are the steps:

1. Create webform1.aspx
2. Copy your aspx code and paste in webform1.aspx
3. Compile your project you should have designer code inside webform1.aspx.designer.cs
4. Now you can copy designer code and use in your original webform.

If you see this while using Visual Basic 2019 and you clicked on the "permanently delete this file" confirmation, you can recover the designer.cs files from your recycle bin...it will regenerate in Visual Basic automatically. I just did it and found my file just as it was.