1 using the base class reference
Examples of the derived class instance of the base class plus the derived class new members composition.
Derived class reference to the entire class object point, comprising a base part
Key: Use reference to the base class part of the object to access the object (the object reference point to the parent class subclass) can only see members of the respective parent class
2 override virtual methods and methods
"Raised" virtual method within a derived class may reference the base class access
@ 1 The method of using the base class virtual method @ 2 are denoted using the derived class override and a method of the base class of the derived class label @ 3 have the same signature and return value
3 abstract class
Abstract method must be achieved unless the class is an abstract class inheritance
4 entrusted the operation of the general flow
@ 1 declare a delegate type
@ 2 using the delegate type to declare a variable commission
@ 3 types of objects created delegate
@ 4 can choose to perform a method of increasing the commission
@ 5 execution request