Visual Studio – Lost nesting of codebehind

We’ve all had times when we’ve created an ASP.NET webpage and then a new page is required with almost identical functionality.

I had that task today and so making things simple I copied the current files, pasted them and made the necessary changes to hook the designer and code-behind files to the aspx page.

This works perfectly. The code builds, the page runs, everything happens as I expected it to.

Then I noticed a little quirk in Visual Studio 2008. One of the great features of Visual Studio is the way in which it visually nests code-behind files in the Solution Explorer under your aspx file.

After making a copy of my origional page I noticed that my code-behind was left astray. I checked all the references to make sure everything was hooked up correctly but still, my code-behind wasn’t nesting nicely under my aspx page as usual.

Now I’m sure many people have come across this problem before however this was a first for me.

It turns out that the references are stores in the csproj file. There is a reference to the code-behind file and a list of dependancies. By default, when doing a copy/paste of files outside of Visual Studio, this reference is not updated and the code-behind file doesn’t attach itself to the aspx file in the Solution Explorer.

The solution is to simply add a reference to the dependant aspx fie in the csproj file like so:

<Compile Include="myShinyNewFile.aspx.cs">
<DependentUpon>myShinyNewFile.aspx</DependentUpon>
<SubType>ASPXCodeBehind</SubType>
</Compile>

Once you’ve added the second line into the csproj file, restarting visual studio brings back the much loved nesting.