无法从Microsoft.Extensions.Logging解析ILogger [英] Unable to resolve ILogger from Microsoft.Extensions.Logging

问题描述

我已经这样配置了控制台应用程序的 Main

I've configured my console application's Main like so

var services = new ServiceCollection()
                .AddLogging(logging => logging.AddConsole())
                .BuildServiceProvider();

然后我尝试在另一个类中使用它

And then I try to use it in another class like so

    private readonly ILogger _logger;

    public MyClass(ILogger logger)
    {
        _logger = logger;
    }

    public void MyFunc()
    {
        _logger.Log(LogLevel.Error, "My Message");
    }

System.InvalidOperationException：'无法解析服务对于类型
'Microsoft.Extensions.Logging.ILogger'

System.InvalidOperationException: 'Unable to resolve service for type 'Microsoft.Extensions.Logging.ILogger'

我已经尝试过解决方案在这里，但它对我不起作用。

I've tried the solutions here but it didn't work for me.

编辑 >
基于Yaakov的以下注释和此Github评论通过执行此操作，我可以正确解决此问题

Edit Based on Yaakov's comment below and this Github comment I'm able to resolve it correctly by doing this

    public MyClass(ILogger<MyClass> logger)
    {
        _logger = logger;
    }

我更希望在最初的中使用它BuildServiceProvider ，但是每次我想使用记录器（或创建自己的ILogger）时，我都要重复一次。

I would have preferred to have this in the initial BuildServiceProvider but looks like I'm gonna have to repeat this every time I want to use the logger (or create my own ILogger).

推荐答案

ILogger 不再默认注册，但 ILogger< T> 已注册。如果仍要使用ILogger，则可以使用以下（Startup.cs）手动注册它：

ILogger is no longer registered by default but ILogger<T> is. If you still want to use ILogger you can registered it manually with the following (Startup.cs):

    public void ConfigureServices(IServiceCollection services)
    {
        var serviceProvider = services.BuildServiceProvider();
        var logger = serviceProvider.GetService<ILogger<AnyClass>>();
        services.AddSingleton(typeof(ILogger), logger);
        ...
     }

AnyClass可以是通用的东西，例如：

Where AnyClass can be something generic, such as:

     public class ApplicationLogs
     {
     }

因此：

        public void ConfigureServices(IServiceCollection services)
        {
            var serviceProvider = services.BuildServiceProvider();
            var logger = serviceProvider.GetService<ILogger<ApplicationLog>>();
            services.AddSingleton(typeof(ILogger), logger);
            ...
         }

ILogger现在将通过构造函数注入进行解析

ILogger will now resolve via constructor injection

这篇关于无法从Microsoft.Extensions.Logging解析ILogger的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！