新手求助，关于私有变量继承的问题

Question

 class Quadrilateral : Shape
    {
        private CColor color;
        //定义四边形的四个顶点
        private Point point1, point2, point3, point4;        public CColor Color
        {
            get
            {
                return color;
            }
            set
            {
                color = value;
            }
        }        public Point Point1
        {
            get
            {
                return point1;
            }
            set
            {
                point1 = value;
            }
        }
        public Point Point2
        {
            get
            {
                return point2;
            }
            set
            {
                point2 = value;
            }
        }
        public Point Point3
        {
            get
            {
                return point3;
            }
            set
            {
                point3 = value;
            }
        }
        public Point Point4
        {
            get
            {
                return point4;
            }
            set
            {
                point4 = value;
            }
        }        public Quadrilateral()
        {
        }
        public Quadrilateral(Point p1, Point p2, Point p3, Point p4)
        {
            point1 = p1;
            point2 = p2;
            point3 = p3;
            point4 = p4;
        }
   class Square : Quadrilateral
    {
        public Square()
        {
        }
        public Square(Point p1, Point p2, Point p3, Point p4)
            : base(p1, p2, p3, p4)
        {
        }在四边形类中，那四个点不都是私有的吗，好像是继承到了正方形中（不是私有变量不能继承吗），为什么不用重新定义，好像是继承到了

Answer 1

base(p1, p2, p3, p4)你这问题和私有变量一点关系都没有，是调用基类构造函数...去看MSDN...

Answer 2

派生类实例都会包含一个完整的基类实例，无论字段私有与否，就像一个大盒子（派生类实例）套着小盒子（基类实例），基类私有的内容确实也到了派生类身体里，只是派生类看不见，但派生类可以通过基类公开的方法来间接访问之，你这个例子就是派生类通过基类公开的构造Quadrilateral(Point p1, Point p2, Point p3, Point p4)来访问基类的私有字段