更多的关于C#中面向对象的概念
Object Oriented Concepts in C#
http://www.c-sharpcorner.com/Code/2003/Dec/OOPS%20In%20CSharp%201.0.asp
Abstract Classes And Methods
http://www.c-sharpcorner.com/Language/AbstractClassesNMethodsRVS.asp
http://www.c-sharpcorner.com/Code/2003/Dec/OOPS%20In%20CSharp%201.0.asp
Abstract Classes And Methods
http://www.c-sharpcorner.com/Language/AbstractClassesNMethodsRVS.asp