Use XProj/SDK project files with ASP.NET Web Apps

The new SDK style project files (sometimes called VS2017 project files, and at one point referred to as xproj files) were not designed to work with ASP.NET Web Application projects. If you’re looking to use the newer SDK project files, then Microsoft is hoping you would use them with ASP.NET Core web apps. However, the SDK project format is soo much easier to work with than the older style, that it’s painful to go back to the old files and their associated packages.configs once you’ve moved to the new style.

So, if you were to convert a .NET 4.8 Web App’s .csproj file to an SDK style project file what are the problems that now occur:

• You can’t target a webapp as an output type with the SDK style project file. The closest you have is the ability to target framework net48 with a library/dll output type (the default type).
  
• I think that might be it?

How do you overcome that challenge:

• If your output type is a library/dll and you set your targetFramework to net48, then you will create an output directory at /bin/{Debug|Release|Xxxx}/net48 which contains all the dlls and other references that would have normally gone into the web app’s /bin folder. So, you are producing the files that you need.
  
• You just need to copy those files into the root /bin folder for IIS/IIS Express to run the website normally. To do that you can add a “CopyToBin” Target to you .csproj file. This target will run after the build completes.
  
• After that, you will want to directly modify the .csproj file  to associate files which are commonly grouped together; such as Web.*.config files.
  

Here is an example:

Unfortunately, if you do this; it will help makes things work on your local machine. But, it won’t really help for your build process. If you use a third party tool to do builds for you, you’ll need to create a custom script which will run after your build completes, but before the results are packaged for deployment. This would need to be a custom solution for your environment. But, the basic outline would look something like this:

• Have your build system check that the .csproj file is (a) building a “web app” (however you define that), (b) a net4X application, and (c) using an SDK style csproj file.
  
  With that many checks needed before performing an action; you know this isn’t a great idea.
  
• Once verified, you’ll want to copy all the normal content files from the source code to a designated output location (css, js, imgs, views?) and then recreate the /bin directory using the output from the build.