如何在 Visual Studio 中快速注入依赖项？

Question

While I was coding on an ASP.NET Core project, and I need some service in my action, like _tokenManager , I have to add a new dependency injection, like this:

Adding a new dependency for a controller takes me at least 3 lines of code so it was not easy. When I need several dependencies it will cost me lots of time.

BTW, while I was changing my code, some dependency may not be necessary and shall be removed. I have to check those dependencies one by one to make sure each of then is necessary. So is there any easy way to automatically add those dependencies when I try to use them and suggest me to remove those not necessary?

It seems that Visual Studio already has this feature. How to enable this feature?

Answer 1

I got a solution.

If you write your injected dependency first, like this:

public class MyController
{
    private readonly MyDependency instance <Ctrl + . here>
    public MyController()
    {
    }
}

Visual Studio won't give you suggestion to complete this.

But if you write your dependency in your constructor first like this:

public class MyController
{
    public MyController(
         MyDependency instance <Ctrl + . here>
        )
    {
    }
}

And Visual Studio 2019 will help you complete it.