In this article, you will learn how ASP. NET page event handling works.
Delegates and events are a fundamental concept yet complex in. NET and C language. This article explains basic concepts of delegates and events and how they are used in a.
NET and C application. Delegates Delegate is one of the base types in. Delegate is a class, which is used to create and invoke delegates at runtime.
It's a new type of object in C. Delegate is very special type of object as earlier the entire the object we used to defined contained data but delegate just contains the details of a method. Need of delegate Programmers often needs to pass a method as a parameter of other methods. For this purpose we create and use delegates.
A delegate is a class that encapsulates a method signature. Although it can be used in any context, it often serves as the basis for the event-handling model in C and. One good way of understanding delegates is by thinking of a delegate as something that gives a name to a method signature.
This makes is possible to programmatically change method calls, and also plug new code into existing classes. As long as you know the delegate's signature, you can assign your own-delegated method.
This ability to refer to a method as a parameter makes delegates ideal for defining callback methods. Delegate magic In class we create its object, which is instance, but in delegate when we create instance that is also referred as delegate means whatever you do you will get delegate.
Delegate does not know or care about the class of the object that it references. Any object will do; all that matters is that the method's argument types and return type match the delegate's. This makes delegates perfectly suited for "anonymous" invocation. Benefits of delegates In simple words delegates are object oriented and type-safe and very secure as they ensure that the signature of the method being called is correct.
Delegates makes event handling simple and easy.Paul Leahy is a computer programmer with over a decade of experience working in the IT industry, as both an in-house and vendor-based developer.
This invokes an exception that is intercepted and logged by the ashio-midori.com code. The text field fires three events: a key-pressed event, a key-typed event, and a key-released event.
Java Event Handling Code.