实例描述

现有某班学生的两份成绩，两份成绩中存在一些不一致的记录。需借助于编程方法找出这些不一致的记录。

实例代码

using System; using System.Collections.Generic; using System.Linq; namespace IntersectAndExceptExp { class Program { static void Main(string[] args) { List<Student> studentList1 = newList<Student>() { new Student(){StudentId=1,Score=64}, new Student(){StudentId=2,Score=85}, new Student(){StudentId=3,Score=78}, new Student(){StudentId=4,Score=94}, new Student(){StudentId=5,Score=90} }; List<Student> studentList2 = newList<Student>() { new Student(){StudentId=1,Score=64}, new Student(){StudentId=2,Score=80}, new Student(){StudentId=3,Score=78}, new Student(){StudentId=4,Score=94}, new Student(){StudentId=5,Score=95} }; var both = studentList1.Intersect(studentList2,new StudentComparer()); var diff1 =studentList1.Except(both, new StudentComparer()); var diff2 =studentList2.Except(both, new StudentComparer()); Console.WriteLine("-------------下面是两份成绩中不同的记录--------------"); Console.WriteLine("-------------第一份学生成绩--------------"); foreach (var s in diff1) { Console.WriteLine("StudentId:"+s.StudentId+";Score:"+s.Score); } Console.WriteLine("-------------第一份学生成绩--------------"); foreach (var s in diff2) { Console.WriteLine("StudentId:"+ s.StudentId + ";Score:" + s.Score); } } } public class Student { public int StudentId { get; set; } public int Score { get; set; } } public class StudentComparer : IEqualityComparer<Student> { public bool Equals(Student x, Studenty) { if (Object.ReferenceEquals(x, y)) returntrue; return x != null && y != null&& x.StudentId == y.StudentId && x.Score == y.Score; } public int GetHashCode(Student obj) { int hashStudentId =obj.StudentId.GetHashCode(); int hashScore =obj.Score.GetHashCode(); return hashStudentId ^ hashScore; } } }

代码说明

先使用Intersect方法生成两份记录的交集，该方法会使用传入的比较器对值进行比较决定记录是否相同。基于前步生成的交集，再使用Except方法找出两份记录中不一致的记录，该方法同样使用传入的比较器对值进行比较决定记录是否相同。

执行结果