What is NonActionAttribute ?

NonAction is an attribute, it is used to represent that a controller method is not an action method. Purpose: We known that all public methods of a controller class are basically treated as action methods. So restrict that we applying Nonaction attribute By using this we changing the default behaviour

If you want to restrict a particular method from accessing Get and Post Method then you represent [Nonaction] attribute

-Usually, MVC consider all public methods of a controller class as action methods. -You can make some of the methods as non action methods by using the NonActionAttribute attribute. example: [NonAction] private void DoSomething() { }

If you want to restrict a particular method from accessing using a url like other action methods and you want to declare that method as public inorder to access it from some other controller then decorate that method with [Nonaction] attribute.

https://msdn.microsoft.com/en-us/library/system.web.mvc.nonactionattribute%28v=vs.118%29.aspx

Which does not come under the category of HTTPGET & HTTPPOST attributes. Its just like a normal method.

This is the action filter attribute, used to indicate this method of controller is not an action method.

Represents an attribute that is used to indicate that a controller method is not an action method. It is already known that all the public methods of a controller class are basically treated as action methods. If you don't want this default behaviour, then you can change the public method with NonActionAttribute. Then, the default behaviour changes.