C#集合排序

 1 List<int> intList = new List<int>() { 1, 2, 3 };
 2             intList.Sort();
 3             foreach (int number in intList)
 4             {
 5                 Console.WriteLine(number);
 6             }
 7             intList.Reverse();
 8             foreach (int number in intList)
 9             {
10                 Console.WriteLine(number);
11             }
12             Console.ReadKey();

 1  class Student
 2     {
 3         private int studentId;
 4         private string studentName;
 5 
 6         public int StudentId { get => studentId; set => studentId = value; }
 7         public string StudentName { get => studentName; set => studentName = value; }
 8         //重写构造方法
 9         public override string ToString()
10         {
11             return "studentId:" + studentId + " studentName:" + studentName;
12         }
13     }

 1    List<Student> studentList = new List<Student>();
 2             Student objStu1 = new Student() { StudentId = 1, StudentName = "小王" };
 3             Student objStu2 = new Student() { StudentId = 2, StudentName = "小李" };
 4             Student objStu3 = new Student() { StudentId = 3, StudentName = "小范" };
 5             studentList.Add(objStu1);
 6             studentList.Add(objStu2);
 7             studentList.Add(objStu3);
 8             studentList.Sort();
 9             foreach (Student objStu in studentList)
10             {
11                 Console.WriteLine(objStu);
12             }
13             Console.ReadKey();

 1   class Student:IComparable<Student>
 2     {
 3         private int studentId;
 4         private string studentName;
 5 
 6         public int StudentId { get => studentId; set => studentId = value; }
 7         public string StudentName { get => studentName; set => studentName = value; }
 8 
 9         //实现接口
10         // 返回结果:
11         //     一个值，指示要比较的对象的相对顺序。 返回值的含义如下：
12         // 值 含义 小于零 此实例在排序顺序中位于 other 之前。 
13         //零 此实例中出现的相同位置在排序顺序中是
14         // other。 大于零 此实例在排序顺序中位于 other 之后。
15         public int CompareTo(Student other)
16         {
17             return this.studentId.CompareTo(other.studentId);
18         }
19 
20         //重写构造方法
21         public override string ToString()
22         {
23             return "studentId:" + studentId + " studentName:" + studentName;
24         }
25     }

 1  class Student : IComparable<Student>
 2     {
 3         private int studentId;
 4         private string studentName;
 5 
 6         public int StudentId { get => studentId; set => studentId = value; }
 7         public string StudentName { get => studentName; set => studentName = value; }
 8 
 9         //实现接口
10         // 返回结果:
11         //     一个值，指示要比较的对象的相对顺序。 返回值的含义如下： 值 含义 小于零 此实例在排序顺序中位于 other 之前。 零 此实例中出现的相同位置在排序顺序中是
12         //     other。 大于零 此实例在排序顺序中位于 other 之后。
13         public int CompareTo(Student other)
14         {
15             return this.studentId.CompareTo(other.studentId);
16         }
17 
18         //重写构造方法
19         public override string ToString()
20         {
21             return "studentId:" + studentId + " studentName:" + studentName;
22         }
23     }
24         //添加4个排序类,并且分别实现排序接口
25         class StuNameASC : IComparer<Student>
26         {
27             public int Compare(Student x, Student y)
28             {
29                 return x.StudentName.CompareTo(y.StudentName);
30             }
31         }
32         class StuNameDESC : IComparer<Student>
33         {
34             public int Compare(Student x, Student y)
35             {
36                 return y.StudentName.CompareTo(x.StudentName);
37             }
38         }
39 
40         class StudentIdASC : IComparer<Student>
41         {
42             public int Compare(Student x, Student y)
43             {
44                 return x.StudentId.CompareTo(y.StudentId);
45             }
46         }
47         class StudentIdDESC : IComparer<Student>
48         {
49             public int Compare(Student x, Student y)
50             {
51                 return y.StudentId.CompareTo(x.StudentId);
52             }
53         }

1 在排序时使用Sort的重载方法  
2 public void Sort(IComparer<T> comparer);
3 传递的是实现这个接口的类的对象
4 studentList.Sort(new StudentIdASC):表示的是按照学号升序排列