ControllerBase

ControllerBase is a foundational abstract class in the Microsoft ASP.NET Core framework, serving as the base for all controller classes. It provides essential functionality and common behaviors that controllers rely upon, such as request handling, model binding, and action result execution. By inheriting from ControllerBase, developers can leverage built-in features like dependency injection, model validation, and HTTP response management without repetitive code.

The class is part of the Microsoft.AspNetCore.Mvc namespace and is designed to work with the Model-View-Controller (MVC) pattern. It introduces core methods like `OnActionExecuting`, `OnActionExecuted`, and `OnResultExecuting`, which allow developers to customize behavior before or after actions are executed. These hooks enable logging, authorization checks, or other cross-cutting concerns without modifying each controller individually.

ControllerBase also handles HTTP request and response objects through properties like `Request` and `Response`, providing direct access to incoming data and outgoing responses. It supports model binding automatically, converting route parameters and form data into strongly typed objects. Additionally, it includes methods for generating URLs (`Url.Action`, `Url.Content`) and managing sessions (`TempData`, `Session`).

While `ControllerBase` is the primary base class for MVC controllers, it is also inherited by `Controller`, which adds additional features like view rendering and client validation. This separation allows developers to use `ControllerBase` in minimal APIs or other scenarios where full MVC functionality is unnecessary. Overall, ControllerBase streamlines controller development by consolidating common infrastructure into a reusable, extensible foundation.