c# - .NET Core - Using system.diagnostics in App.config

Question

I'm migrating a console app from .NET Legacy to .NET Core 2.2. In that app, I'm using the HttpClient and HttpRequestMessage classes. Sometimes, requests made with these classes fail. For that reason, I had a system.diagnostics block in my App.config file to log the raw request for diagnosing issues. While this worked in my legacy app, I now get an error in .NET Core.

When I start my app, I see the following error:

ConfigurationErrorsException: Unrecognized configuration section system.diagnostics. 

The only thing I've added to my App.config file is: <system.diagnostics></system.diagnostics>, which is an empty config block. If I remove that block, my app runs as expected.

How do I add the system.diagnostics configuration used in my legacy app into my .NET Core app so I can trace the raw web requests again?

Thanks!

Answer 1

The thing is that .NET Core doesn't pre-register config section for system.diagnostics.

Try to emplace this at the beginning of App.config, just under <configuration> line:

<configSections>
    <section name="system.diagnostics" type="System.Diagnostics.DiagnosticsConfigurationHandler"/>
</configSections>