C # event is empty

Principle:

1. If no event handler is written for the event, then the event (also a class, class object) is empty

2, the above mentioned

event = = Delegate (event handler)

This syntax-formatted statement simply associates the event with the event handler, and at this point the event handler is already defined, because the call to the event handler, which indicates which function to use when the event occurs, indicates that the This association is written in the event receiver (the general user code is in the event receiver, such as system events are issued by the system, the receiver is associated with a custom event handler to implement a variety of functional applications);

The event is raised on the event sender side and is typically implemented using the following code

if (EventObject!= null)

{

EventObject (sender, Ev);

}

When the event handler is defined, the eventobject is not null, at which point the event is raised with the EventObject (sender, EV) statement, which is equivalent to the SendMessage effect in C