无法从Microsoft.Extensions.Logging解析ILogger

本文介绍了无法从Microsoft.Extensions.Logging解析ILogger的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 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