LoggerFactory 生成了 InvalidOperationException。

Question

我使用Microsoft.Extensions.Logging创建了一个控制台应用程序，它使用了服务层。

Program.cs

public static void Main(string[] args)
{
    // Create service collection
    var serviceCollection = new ServiceCollection();
    ConfigureServices(serviceCollection);

    // Create service provider
    var serviceProvider = serviceCollection.BuildServiceProvider();

    // Entry to run app
    serviceProvider.GetService<App>().Run().RunSynchronously();
}

private static void ConfigureServices(IServiceCollection serviceCollection)
{
    // Configuration
    var configuration = new ConfigurationBuilder()
        .SetBasePath(Directory.GetCurrentDirectory())
        .AddJsonFile("appsettings.json", false)
        .Build();

    serviceCollection.AddOptions();
    serviceCollection.Configure<Settings>(options =>
    {
        //...
    });

    // Services
    serviceCollection.AddTransient<IOneService, OneService>();
    serviceCollection.AddTransient<ISecondService, SecondService>();

    // Repositories
    serviceCollection.AddTransient<MyContext, MyContext>();
    serviceCollection.AddTransient<IOneRepository, OneRepository>();

    // App
    serviceCollection.AddTransient<App>();

    // Logger

    // Automapper
    serviceCollection.AddSingleton(new AutoMapperProfileConfiguration());
    serviceCollection.AddScoped<IMapper>(sp =>
        new Mapper(sp.GetRequiredService<IConfigurationProvider>(), sp.GetService));
}

我遇到了以下错误：

System.InvalidOperationException: 无法解析类型 'Microsoft.Extensions.Logging.ILogger`1

我猜想我需要设置 LoggerFactory 和 Microsoft.Extensions.Logging 以进行 .NET Core 日志记录，但是我无法正确设置。

我尝试在 Main() 中添加了类似以下代码：

// Attempt 1
ILoggerFactory loggerFactory = new LoggerFactory()
    .AddConsole()
    .AddDebug();
ILogger logger = loggerFactory.CreateLogger<Program>();
logger.LogInformation(
  "This is a test of the emergency broadcast system.");
  
// Attempt 2
serviceCollection.AddSingleton(new LoggerFactory()
    .AddConsole()
    .AddDebug());
    

有什么想法吗？

- Gerald Hughes

---

你忘记在服务集合上调用.AddLogging()来将该功能添加到容器中了。 - Nkosi

Answer 1

应该可以工作:

var serviceProvider = new ServiceCollection()
                      .AddLogging() //<-- You were missing this
                      .BuildServiceProvider();
//get logger
var logger = serviceProvider.GetService<ILoggerFactory>()
            .CreateLogger<Program>();

需要安装的包：Microsoft.Extensions.DependencyInjection；Microsoft.Extensions.Logging;

- OlegI

Answer 2

对于 netCore

var serviceProvider = new ServiceCollection()
    .AddLogging(x => x.AddConsole().SetMinimumLevel(LogLevel.Debug))
    .BuildServiceProvider();

var logger = serviceProvider.GetService<ILoggerFactory>()
    .CreateLogger<Program>();

logger.LogDebug("Starting Program...");

- DanielV