Logging with ILogger

The ILogger class is part of the Microsoft.Extensions.Logging.Abstractions NuGet package. If you work on an ASP.NET Core application, worker service, or use other Microsoft.Extensions packages, you already depend on it transitively.

The ILogger interface exposes a few methods:

• Log records a log message with a given level, ID, exception, state, and formatter. The state type is generic but should contain a message, along with all the parameters and their names.
• IsEnabled checks whether logging at this level is enabled.
• BeginScope adds an object to the logging scope, allowing you to enrich nested log records with it. We saw scopes in action in Chapter 2, Native Monitoring in .NET, where we annotated console logs with trace context and ASP.NET Core request information.

It’s common to use convenient extension methods defined in the Microsoft.Extensions.Logging.LoggerExtensions class instead of the vanilla ILogger.Log method.

Before...