C#继承基类和派生类

using System;

namespace InheritanceApplication {

   class Shape {

      public void setWidth(int w) {
         width = w;
      }

      public void setHeight(int h) {
         height = h;
      }
      protected int width;
      protected int height;
   }

   // Derived class
   class Rectangle: Shape {

      public int getArea() { 
         return (width * height); 
      }
   }

   class RectangleTester {

      static void Main(string[] args) {
         Rectangle Rect = new Rectangle();

         Rect.setWidth(5);
         Rect.setHeight(7);

         // Print the area of the object.
         Console.WriteLine("Total area: {0}",  Rect.getArea());
         Console.ReadKey();
      }
   }
}