使用Linq的Intersect与Except方法的实例

来源：互联网发布：绘图软件上色教学编辑：程序博客网时间：2024/06/05 09:01

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

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