Object-oriented (delegate)

Commissioned:
Also known as the agent, the event is also a delegate;
Defined at the outermost of the class

1. Define the delegate
Keyword: delegate
Function Signature: Signature and function remain consistent
When defining a delegate, you define it according to the function.
public delegate int first (int a,int b);
The return type of the method pointed to requires the parameters to be consistent!

2. Defining the delegate variable, pointing to the method

A delegate cannot be instantiated because it is not a class;

First F = new Jiafa; New delegate variable, point to method, note!! method does not need parentheses!!

The second time you can use + =

public int Jiafa (int a,int b)
{
return a+b;
}

Call:
f (5,3);

Can be understood as a pointer to a function, which function the delegate points to, which function is represented by the delegate
Allows functions to be passed as arguments

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Object-oriented (delegate)