How do you create an Action Filter?

An ActionFilter can be created in two ways:

1. Implement the IActionFilter interface
2. Extend the ActionFilterAttribute abstract class

IActionFilter contains two methods, that the custom Action Filter needs to implement:

OnActionExecuting(ActionExecutingContext ctx) - before action is executed
OnActionExecuted(ActionExecutedContext ctx) - after action is executed

ActionFilterAttribute abtract class has the below methods which can be overriden as required:

OnActionExecuting(ActionExecutingContext ctx) - before action is executed
OnActionExecuted(ActionExecutedContext ctx) - after action is executed
OnResultExecuting(ResultExecutingContext ctx) - before the ActionResult instance is invoked
OnResultExecuted(ResultExecutedContext ctx) - after the ActionResult instance is invoked