Biegral Blog

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Duotai_test
{
    //定义一个基类
    public class DrawingObject
    {
        public virtual void Draw()
        {
            Console.WriteLine("一个通用的图像对象");
        }
    }
    //定义一个直线类
    public class Line : DrawingObject 
    {
        public override void Draw()
        {
            Console.WriteLine("一条直线");
        }
    }
    //定义一个圆周类
    public class Circle : DrawingObject 
    {
        public override void Draw()
        {
            Console.WriteLine("一个圆");
        }
    }
    //定义一个正方形类
    public class Square : DrawingObject
    {
        public override void Draw()
        {
            Console.WriteLine("一个正方形");
        }
    }
    public class DrawDemo
    {
        public static void Main()
        {
            DrawingObject[] dObj = new DrawingObject[4];      //重点
            dObj[0] = new Line();
            dObj[1] = new Circle();
            dObj[2] = new Square();
            dObj[3] = new DrawingObject();
            foreach (DrawingObject drawObj in dObj)
            {
                drawObj.Draw();
            }
        }
    }
}