C# 自定义类型数组的排序

Posted 2020-06-24 勿在浮沙筑高台

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Threading.Tasks;
 6 
 7 namespace 数组排序
 8 {
 9     /// <summary>
10     /// IComparable : 接口
11     /// </summary>
12     public class Student : IComparable
13     {
14         public int ID { get; set; }
15         public string Name { get; set; }
16         public int Age { get; set; }
17 
18         /// <summary>
19         /// 重写ToString方法
20         /// </summary>
21         /// <returns></returns>
22         public override string ToString()
23         {
24             return String.Format("ID={0} \t Name={1} \t Age={2}", this.ID, this.Name, this.Age);
25         }
26 
27         /// <summary>
28         /// 实现IComparable接口的CompareTo()方法来通过【Age】来进行排序
29         /// </summary>
30         /// <param name="obj"></param>
31         /// <returns>1:大于 -1:小于 0:等于</returns>
32         public int CompareTo(object obj)
33         {
34             Student student = (Student)obj;
35             if ( this.Age > student.Age)
36             {
37                 return 1;
38             }
39             if (this.Age < student.Age)
40             {
41                 return -1;
42             }
43             return 0;
44         }
45     }
46 
47     class Program
48     {
49         static void Main(string[] args)
50         {
51             Student[] student = 
52             {
53                 new Student(){ID = 001, Name = "张三", Age = 15},
54                 new Student(){ID = 002, Name = "李四", Age = 16},
55                 new Student(){ID = 003, Name = "王五", Age = 18},
56                 new Student(){ID = 004, Name = "赵六", Age = 14}
57             };
58 
59             //Console.WriteLine(student);     // 打印结果: 数组排序.Student[]
60             //Console.WriteLine(student[1]);    // 打印结果: ID=002, Name="李四", Age=16
61             
62             Console.WriteLine("student数组未进行排序前:");
63             for (int i = 0; i < student.Length; ++i )
64             {
65                 Console.WriteLine("student[{0}] : {1}", i, student[i]);
66             }
67             
68             /// Array.Sort():数组的静态方法:默认升序排列
69             Array.Sort(student);
70             Console.WriteLine("\n=================按照【Age】升序排序后===================");
71             foreach (var v in student)
72             {
73                 Console.WriteLine(v); //默认调用Student的ToString()方法
74             }
75 
76             /// Array.Reverse()方法:反转整个一维数组的元素顺序
77             /// 如果要实现【降序】排列,则必须先通过Array.Sort(数组)的方法先将数组按升序有序排列后,再
78             /// 调用Array.Reverse()方法反转数组的元素,实现降序排列.
79             /// 如果要实现自定义类型的数组排序,则必须要
80             Array.Reverse(student);
81             Console.WriteLine("\n=================按照【Age】降序排序后===================");
82             foreach (Student st in student)
83             {
84                 Console.WriteLine(st);
85             }
86 
87             Console.ReadLine();
88         }
89     }
90 }