title: Application Settings in .Net Core (WPF) and single exe
body: <p>To migrate an application I want to continue using the plain old settings that still come along with .Net5 (App.Config, Settings.settings and so on).<br>
  I need a simple built in solution without additional dependencies.</p>
  <p>The proposed way seems to be appsettings.json or similar.<br/>
  For that to use with WPF you need to add some additonal dependencies which bloat the project when
  publishing it as single exe (not self contained). It is over-the-top for simple applications.</p>
  <p>I followed the steps here:
  <a href="https://stackoverflow.com/questions/56847571/equivalent-to-usersettings-applicationsettings-in-wpf-dotnet-core">Equivalent to UserSettings / ApplicationSettings in WPF dotnet core</a>
  The accepted answer from Alexander works for a normal exe built.</p>
  <p>These are the generated files<br/>
  MyApp.dll<br/>
  MyApp.dll.config<br/>
  MyApp.exe<br/></p>
  <p>Modifying &quot;MyApp.dll.config&quot; with an editor directly reflects the changed data in the code.</p>
  <pre><code>MessageBox.Show(Settings.Default.SomeConfigValue);
  </code></pre>
  <p>The used config file can be displayed using</p>
  <pre><code>var config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
  MessageBox.Show(config.FilePath);
  </code></pre>
  <p>It displays<br/>
  <strong>C:\Projekte\MyApp\MyApp\bin\Debug\net5.0-windows\MyApp.dll.config</strong></p>
  <p>Unfortunately this fails for single exe</p>
  <p>These are the generated files (in publish folder)<br/>
  MyApp.dll.config<br/>
  MyApp.exe<br/></p>
  <p>Modifying &quot;MyApp.dll.config&quot; or &quot;MyApp.exe.config&quot; has no effect. The file does not seem to be used by the framework.<br/>
  Above messagebox now shows<br/>
  <strong>C:\Projekte\MyApp\Publish&lt;Unknown&gt;.config</strong></p>
  <p>How to get the built-in configuration system work with single exe?</p>