.net core resolve dependency manually anywhere in the code

Question

Do you know how to manually resolve dependencies in .net core? Something like

DependencyResolver.Resolve<ISomeService>()

UPDATE I'm in a class that was not injected, I want to resolve it from the inside, rather than pass variables all over the place

Answer 1

Add your dependency in ConfigureServices as below

public void ConfigureServices(IServiceCollection services){
    //AddSingleton or AddTransient based on your requirements
    services.AddTransient<ISomeService, ConcreteService>();
}

In your controller or anywhere, add IServiceProvider in the constructor like below:

using Microsoft.Extensions.DependencyInjection;

...

public class HomeController
{
  ...
  public HomeController(IServiceProvider serviceProvider)
  {
      var service = serviceProvider.GetService<ISomeService>();
  }
}

@Shazam, Here are some notes or suggestions based on your comment:

• If you can not inject because you might not have a constructor in this class, I woud suggest to add a paramter to your function and pass the resolved dependency from outside

• Another Idea is to add a static property and initialize its value in ConfigureServices

For Example:

public static class MyClass
{
    public static ISomeService MyServiceObj { set; get; }
    ....
}

In your ConfigureServices

   public void ConfigureServices(IServiceCollection services){
        services.AddTransient<ISomeService, ConcreteService>();
        MyClass.MyServiceObj = services.GetService<ISomeService>();
    }

Hope this helps, please rate my answer or leave me a comment if you still in doubt how to do it