In ASP.NET MVC, action filters are attributes that can be applied to controller actions or the entire controller itself to modify or enhance the behavior of the action method during its execution. They are used to inject additional processing logic before, during, or after the execution of the controller action.
Action filters can be used for a variety of purposes, such as authentication, authorization, caching, logging, exception handling, and more. They provide a way to intercept the execution of a controller action and add custom logic to it.
there are four types of action filters:
Authorization filters
These filters are used to authenticate the user and check if the user has the required permissions to access a particular action method or controller.
Action filters
These filters are used to execute code before and after an action method is called. They can be used to modify the action method's input or output, perform validation, or add or modify response headers.
Result filters
These filters are used to modify the result of an action method before it is returned to the client. They can be used to modify the response status code, add or modify response headers, or transform the response body.
Exception filters
These filters are used to handle exceptions that occur during the execution of an action method. They can be used to log the exception, modify the response, or redirect the user to an error page.
Action filters can be applied at the controller level or the action level. They can also be applied globally to all controllers and actions using the MVC middleware.
