Is ApiController deprecated in .NET Core

Question

Is it true that "ApiController will get deprecated in .NET Core"? Asking since I'm planning to use it in new projects.

Answer 1

Update ASP.NET Core 2.1

Since ASP.NET Core 2.1 a new set of types is available to create Web API controllers. You can annotate your controllers with the [ApiController] attribute which enables a few new features such as automatic model state validation and binding source parameter inference. See the docs for more information: https://docs.microsoft.com/en-us/aspnet/core/web-api/index?view=aspnetcore-2.1#annotate-class-with-apicontrollerattribute.

---

There is indeed no particular ApiController class anymore since MVC and WebAPI have been merged in ASP.NET Core. However, the Controller class of MVC brings in a bunch of features you probably won't need when developing just a Web API, such as a views and model binding.

You've got two options if you want something different:

Use the ControllerBase class in the Microsoft.AspNetCore.Mvc.Core package.

Or

Create your ApiController base class. The key here is to add the [ActionContext] attribute which injects the current ActionContext instance into the property:

[Controller] public abstract class ApiController {     [ActionContext]     public ActionContext ActionContext { get; set; } } 

Also, add the [Controller] attribute to the class to mark it as a controller for the MVC controller discovery.

See more details in my “Web API in MVC 6” blogpost.

Answer 2

The [ApiController] attribute actually got added back in ASP.NET Core version 2.1.

Features coupled with the attribute are:

• Validation errors automatically trigger an HTTP 400 response.
• No more need to define [FromBody], [FromRoute], ... attributes explicitly

Links to the docs:

• https://docs.microsoft.com/en-us/aspnet/core/aspnetcore-2.1?view=aspnetcore-2.1#apicontroller-actionresult
• https://docs.microsoft.com/en-us/aspnet/core/web-api/index?view=aspnetcore-2.1#annotate-class-with-apicontrollerattribute

Update

There is also the baseclass ControllerBase for controllers to inherit from which is suited for api-controllers because it ommits all view-related functionality.

• https://docs.microsoft.com/en-us/dotnet/api/microsoft.aspnetcore.mvc.controllerbase?view=aspnetcore-2.1