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 }
