.Net core 2.0控制台应用程序的日志记录和配置？

Question

以下代码得到了错误.为.Net Core 2.0控制台应用程序设置日志记录和配置管理的正确方法是什么？

错误CS1061'LoggerFactory'不包含'AddConsole'的定义,并且没有可以找到接受类型'LoggerFactory'的第一个参数的扩展方法'AddConsole'(您是否缺少using指令或程序集引用？)

错误CS1503参数2:无法从"Microsoft.Extensions.Configuration.IConfigurationSection"转换为"System.Action"

class Program
{
    static void Main(string[] args)
    {
        var services = new ServiceCollection();
        ConfigureServices(services);
        var serviceProvider = services.BuildServiceProvider();
        var app = serviceProvider.GetService<Application>();
        Task.Run(() => app.Run()).Wait();
    }

    private static void ConfigureServices(IServiceCollection services)
    {
        ILoggerFactory loggerFactory = new LoggerFactory()
            .AddConsole() // Error!
            .AddDebug();

        services.AddSingleton(loggerFactory); // Add first my already configured instance
        services.AddLogging(); // Allow ILogger<T>

        IConfigurationRoot configuration = GetConfiguration();
        services.AddSingleton<IConfigurationRoot>(configuration);

        // Support typed Options
        services.AddOptions();
        services.Configure<MyOptions>(configuration.GetSection("MyOptions")); // Error!

        services.AddTransient<Application>();
    }

    private static IConfigurationRoot GetConfiguration()
    {
        return new ConfigurationBuilder().SetBasePath(Directory.GetCurrentDirectory()).AddXmlFile("App.config", optional: true).Build();
    }

    public class MyOptions
    {
        public string Name { get; set; }
    }

    public class Application
    {
        ILogger _logger;
        MyOptions _settings;

        public Application(ILogger<Application> logger, IOptions<MyOptions> settings)
        {
            _logger = logger;
            _settings = settings.Value;
        }

        public async Task Run()
        {
            try
            {
                _logger.LogInformation($"This is a console application for {_settings.Name}");
            }
            catch (Exception ex)
            {
                _logger.LogError(ex.ToString());
            }
        }
    }
}

Answer 1

它看起来你可能会遗漏几个依赖项:

1. Microsoft.Extensions.Logging.Console,它提供了AddConsole扩展方法.
2. Microsoft.Extensions.Options.ConfigurationExtensions,它提供了Configure<T>您似乎缺少的扩展方法.

在.NET核心可执行文件配置服务方面,安德鲁锁具有后对.NET核心的第一个版本的话题.其中一些可能已经过时了.NET Core 2最近的到来,但值得一读.

Answer 2

在Kirk Larkins的基础上回答(确保你有nuget软件包安装),你可以简化日志记录配置并通过传入一个Microsoft.Extensions.Options.ConfigurationExtensions来跳过loggerFactory的声明Microsoft.Extensions.Logging.Console:

public static IServiceProvider ConfigureServices(IServiceCollection serviceCollection)
{
    //ILoggerFactory loggerFactory = new LoggerFactory()
    //  .AddConsole()
    //  .AddDebug();

    serviceCollection
        .AddLogging(opt =>
        {
            opt.AddConsole();
            opt.AddDebug();
        })
        .AddTransient<IFooService, FooService>();

    /*... rest of config */

    var serviceProvider = serviceCollection.BuildServiceProvider();
    return serviceProvider;
}