将日志(Microsoft.Extensions.Logging)添加到.NET Core控制台应用程序

在.NET Core项目中，日志记录是通过依赖项注入进行管理的。 尽管这对于ASP.NET项目效果很好，但在启动Startup.cs中的新项目时，所有这些都会自动创建，而在控制台应用程序中则需要一些配置才能使其启动并运行。

这大部分是从此处的博客文章整理而成的，但我对其进行了修改。

该项目是在Visual Studio 2019中创建的，并且需要以下程序包（在csproj文件中找到）

<ItemGroup>
    <PackageReference Include="Microsoft.Extensions.Configuration" Version="3.1.0" />
    <PackageReference Include="Microsoft.Extensions.Configuration.FileExtensions" Version="3.1.0" />
    <PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="3.1.0" />
    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="3.1.0" />
    <PackageReference Include="Microsoft.Extensions.Logging" Version="3.1.0" />
    <PackageReference Include="Microsoft.Extensions.Logging.Console" Version="3.1.0" />
    <PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="3.1.0" />
  </ItemGroup>

该项目中的业务逻辑在服务中得到处理，而Program.cs用于引导运行应用程序所需的一切。 需要在app-settings.json的“ ConnectionStrings”部分中添加一个“Logging”配置，该条目可以像这样添加到控制台应用程序中。

app-settings.json

{
  "Logging": {
    "LogLevel": {
      "Default": "Debug",
      "System": "Information",
      "Microsoft": "Information"
    },
    "Console": {
      "IncludeScopes": true
    }
  }
}

Program.cs

  public class Program
    {
        public static void Main(string[] args)
        {
            var serviceCollection = new ServiceCollection();
            ConfigureServices(serviceCollection);
            var serviceProvider = serviceCollection.BuildServiceProvider();
            var run = serviceProvider.GetService<App>();
            if (run != null)
                run.Run();
            else
                System.Console.WriteLine("Init Error");
        }

        private static void ConfigureServices(IServiceCollection services)
        {
            var configuration = new ConfigurationBuilder()
                .SetBasePath(Directory.GetCurrentDirectory())
                .AddJsonFile("app-settings.json", false)
                .Build();

            services.AddLogging(loggingBuilder =>
            {
                loggingBuilder.AddConfiguration(configuration.GetSection("Logging"));
                loggingBuilder.AddConsole();
                loggingBuilder.AddDebug();
            });

            // Add access to generic IConfigurationRoot
            services.AddSingleton(configuration);

            // Add services
            services.AddTransient<IBackupService, BackupService>();

            // Add app
            services.AddTransient<App>();
        }
    }

App.cs

   public class App
    {
        private readonly IBackupService _backupService;
        private readonly ILogger<App> _logger;
        private readonly IConfigurationRoot _config;

        public App(ILogger<App> logger, IBackupService backupService, IConfigurationRoot config)
        {
            _logger = logger;
            _backupService = backupService;
            _config = config;
        }

        public void Run()
        {
            _logger.LogInformation($"Running application.");
            _backupService.Run();
            System.Console.ReadKey();

        }
    }

BackupService.cs

  public interface IBackupService
    {
        void Run();
    }

 public class BackupService : IBackupService
    {
        private readonly ILogger<BackupService> _logger;
        private readonly IConfigurationRoot _config;

        public BackupService(ILogger<BackupService> logger, IConfigurationRoot config)
        {
            _logger = logger;
            _config = config;
        }

        public void Run()
        {
            _logger.LogDebug($"Running backup service.");
        }
    }