问题
Is this:
Button.Click -= new EventHandler(Button_Click);
the same as this:
Button.Click -= Button_Click;
I ask because to me it seems that the former is removing a new reference to a method, and the latter one is removing a method itself. But then again, maybe the new EventHandler part is implicit in the += or -= overload in case the programmer doesn't explicitly assign it like that?
In case it is different how about
Button.Click -= new EventHandler(Button_Click);
VS
Button.Click -= Button_Click;
Thanks.
回答1:
It is the same. The second is merely syntactic sugar for the first, and equality comparison is overloaded appropriately for delegate types:
Two delegates of the same type with the same targets, methods, and invocation lists are considered equal.
Source: MSDN, Delegate.Equality Operator
回答2:
The end result is the same. The compiler is inferring the type of delegate automatically and as a result the new operator is not required to create it.
来源：https://stackoverflow.com/questions/1307607/removing-event-handlers