Controllers and Actions
Learn about the role of controllers in ASP.NET Core MVC, introducing ControllerBase for web services and Controller for views.
In MVC, the C stands for the controller. From the route and an incoming URL, ASP.NET Core knows the name of the controller, so it will then look for a class that is decorated with the [Controller] attribute or derives from a class decorated with that attribute, for example, the Microsoft-provided class named ControllerBase, as shown in the following code:
namespace Microsoft.AspNetCore.Mvc{//// Summary:// A base class for an MVC controller without view support.[Controller]public abstract class ControllerBase{...
The ControllerBase class
As we can see in the XML comment, ControllerBase does not support views. It is used for creating web services, as seen in the Building and Consuming Web Services. ControllerBase has many useful properties for working with the current HTTP context, as shown in the following table:
Property | Description |
Request | Just the HTTP request. For example, headers, query string parameters, the body of the request as a stream that you can read from, the content type and length, and cookies. |
Response | Just the HTTP response. For example, headers, the body of the response as a stream that you can write to, the content type and length, status code, and cookies. There are also delegates like OnStarting and OnCompleted that you can hook a method up to. |
HttpContext | Everything about the current HTTP context including the request and response, information about the connection, a collection of features that have been enabled on the server with middleware, and a User object for authentication and authorization. |