无法在dotnet core 2.1中注册日志记录

Question

我创建了一个新的dotnet核心项目，该项目发布：dotnet new mvc -au none -o aspnet_app然后按照本指南向应用程序添加日志记录所以我将COnfigureLogging添加到Program.BuildWebHostpublic static IWebHost BuildWebHost(string[] args) =>    WebHost.CreateDefaultBuilder(args)        .ConfigureLogging((hostContext, logging) =>         {            logging.AddConfiguration(hostContext.Configuration.GetSection("Logging"));            logging.AddConsole();        })        .UseStartup<Startup>()        .Build();并且还修改了Startup.cspublic void ConfigureServices(IServiceCollection services){    services.AddLogging();    services.AddMvc();}但是当我在HomeController中尝试使用它时：private readonly ILogger<HomeController> _logger;public HomeController(ILogger<HomeController> logger) {    _logger = logger;}public IActionResult Index(){    _logger.LogInformation("Index action!");    return View();}我收到以下错误：fail: Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware[0]  An unhandled exception has occurred: Unable to resolve service for type 'Microsoft.Extensions.Logging.ILogger' while attempting to activate 'aspnet_app.Controllers.HomeController'.--使用dotnet core 2.1.105

Answer 1

您正在对它进行编码。 CreateDefaultBuilder生成自动获取

hostContext.Configuration.GetSection（“ Logging”）的记录器， 您实际上不需要在program.cs或启动中添加注释。

只需编辑基本项目并添加它，它将起作用。

public HomeController(ILogger<HomeController> logger)

    {

        _logger = logger;

    }

    public IActionResult Index()

    {

        _logger.LogInformation("Index action!");

        return View();

    }