代码中为每个形状指定了序号，如果再来一颗子弹，让你要按类型打印的同时，还要按照序号从小到大排列怎么做呢？

  1 using System;
  2 using System.Collections.Generic;
  3 
  4 namespace DesignPattern
  5 {
  6     class Program
  7     {
  8         public static readonly string[] OrderStrings =
  9         {
 10             nameof(Square),
 11             nameof(Circle), 
 12             null
 13         };
 14 
 15         static void Main(string[] args)
 16         {
 17             // 产生若干个随机图形
 18             Random random = new Random();
 19             var shapes = new List<Shape>();
 20             for (int i = 0; i < 100; i++)
 21             {
 22                 var value = random.Next(0, 10);
 23                 if (value < 5)
 24                 {
 25                     shapes.Add(new Square() { Index = i });
 26                 }
 27                 else
 28                 {
 29                     shapes.Add(new Circle() { Index = i });
 30                 }
 31             }
 32 
 33             // 画出所有随机图形
 34             //shapes.ForEach(shape => shape.Draw());
 35 
 36             // 并发画出所有随机图形
 37             //Parallel.ForEach(shapes, shape => { shape.Draw(); });
 38 
 39             // 按先圆形后正方形的顺序画出所有图形
 40             shapes.Sort(
 41                 (shape, shape1) =>
 42                 {
 43                     if (shape < shape1)
 44                     {
 45                         return -1;
 46                     }
 47 
 48                     if (shape > shape1)
 49                     {
 50                         return 1;
 51                     }
 52 
 53                     return 0;
 54                 });
 55             shapes.ForEach(shape => shape.Draw());
 56 
 57             Console.ReadLine();
 58         }
 59     }
 60     
 61     public class Shape
 62     {
 63         public int Index { get; set; }
 64 
 65         public virtual void Draw()
 66         {
 67             Console.WriteLine($"画了Shape基类{Index}");
 68         }
 69 
 70         public static bool operator <(Shape left, Shape right)
 71         {
 72             var leftTypeName = left.GetType().Name;
 73             var leftIndex = -1;
 74             var rightTypeName = right.GetType().Name;
 75             var rightIndex = -1;
 76             for (int i = 0; i < Program.OrderStrings.Length; i++)
 77             {
 78                 if (leftTypeName == Program.OrderStrings[i])
 79                 {
 80                     leftIndex = i;
 81                 }
 82 
 83                 if (rightTypeName == Program.OrderStrings[i])
 84                 {
 85                     rightIndex = i;
 86                 }
 87             }
 88             return leftIndex < rightIndex;
 89         }
 90 
 91         public static bool operator >(Shape left, Shape right)
 92         {
 93             return !(left < right);
 94         }
 95     }
 96 
 97     public class Square:Shape
 98     {
 99         public override void Draw()
100         {
101             Console.WriteLine($"画了正方形{Index}");
102         }
103     }
104 
105     public class Circle : Shape
106     {
107         public override void Draw()
108         {
109             Console.WriteLine($"画了圆{Index}");
110         }
111     }
112 }

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