How to not copy app.config file to output directory

David picture David · Oct 27, 2016 · Viewed 11.7k times · Source

I have a WPF application I am building. I am using Visual Studio Community 2015. In an effort to create a "true" release build, I am changing up some build settings so it only generates necessary files that will be installed on the user's computer. So no vshost exe, no generated XML files, etc. etc. etc. (I am retaining PDB file generation, however).

I have everything exactly how I want it, except for one file. I have an App.config file in each project. I don't mind this getting copied to the output directory on my debug builds, but on my "true" release build I don't want it there.

The file is already set as "Do not copy" in its properties. See images below:

App.config image

Despite having the "Do not copy" setting, however, I still get an "MyAppName.exe.config" file generated every single time I build the project. Why is this so? How can I turn it off? It is quite annoying.

Thanks for any advice!

Answer

Rolo picture Rolo · Oct 27, 2016

The handling of app.config is special, it is treated By Name, the build process will select the app.config file following this order:

  • Choose the value $(AppConfig) set in the main project.
  • Choose @(None) App.Config in the same folder as the project.
  • Choose @(Content) App.Config in the same folder as the project.
  • Choose @(None) App.Config in any subfolder in the project.
  • Choose @(Content) App.Config in any subfolder in the project.

$(AppConfig) is an MSBuild Property, if it is empty, it will look for a file with name "App.Config" in the "None" or "Content" MSBuild Item Groups, if there's a match, the file will be used and will be copied to the output directory replacing the app.config name by [AssemblyName].config

If you want to keep the file without delete it, you will need to change the "Build Action" property to something different to "None" or "Content", you can use any existing value on the list (I suggest "AdditionalFiles") or any value you want to use i.e. "MyConfigFile", and now the that will keep the file inside the project, but without the logic that generates the configuration file in the output directory.

Or you can rename the file to something different than "app.config" and keep the current property values for "Build Action" and "Copy to Output Directory".