Unable to resolve service for type 'Microsoft.Extensions.Logging.ILogger`1[WebApplication1.Startup]'

Question

I created an ASP.NET Core 3.0 Web Application with the default template in Visual Studio 2019 Preview 2.2 and tried to inject an ILogger in Startup:

namespace We         


        

Answer 1

If you want to log things after the Configure() has been called, you can still inject the ILogger via method injection (as opposed to the preferred constructor injection:

public void Configure(IApplicationBuilder app, IWebHostEnvironment env, ILogger logger)
{
     _logger = logger;
     ...
}