两数组并集交集差集

using System;
using System.Collections.Generic;
using System.Linq;

namespace ServiceTest
{
    class Program
    {
        static void Main(string[] args)
        {
            IList<Student> oneStudents = new List<Student>();
            oneStudents.Add(new Student(1, false, "小新1", "one"));
            oneStudents.Add(new Student(2, false, "小新2", "one"));

            IList<Student> twoStudents = new List<Student>();

            twoStudents.Add(new Student(2, false, "小新2", "two"));
            twoStudents.Add(new Student(2, false, "小新22", "two"));
            twoStudents.Add(new Student(3, false, "小新3", "two"));

            var bingji = oneStudents.Union(twoStudents, new StudentListEquality()).ToList();//并（全）集 
            var jiaoji = oneStudents.Intersect(twoStudents, new StudentListEquality()).ToList();//交集 
            var chaji = oneStudents.Except(twoStudents, new StudentListEquality()).ToList();//差集
            var weiyi = twoStudents.Distinct(new StudentListEquality()).ToList();
            Console.WriteLine();
            Console.WriteLine("以下是并集的结果");
            bingji.ForEach(x =>
            {
                Console.WriteLine(x.StudentId.ToString() + "    " + x.Sex.ToString() + "   " + x.Name.ToString() + " " + x.Address.ToString());
　　　　　　　　　　
            });
            Console.WriteLine();
            Console.WriteLine("以下是交集的结果");
            jiaoji.ForEach(x =>
            {
                Console.WriteLine(x.StudentId.ToString() + "    " + x.Sex.ToString() + "   " + x.Name.ToString() + " " + x.Address.ToString());

            });

            Console.WriteLine();
            Console.WriteLine("以下是差集的结果");
            chaji.ForEach(x =>
            {
                Console.WriteLine(x.StudentId.ToString() + "    " + x.Sex.ToString() + "   " + x.Name.ToString() + " " + x.Address.ToString());

            });
            Console.WriteLine();
            Console.WriteLine("以下是唯一的结果");
            weiyi.ForEach(x =>
            {
                Console.WriteLine(x.StudentId.ToString() + "    " + x.Sex.ToString() + "   " + x.Name.ToString() + " " + x.Address.ToString());

            });

            Console.ReadLine();
            //new SignVerifyUnifiedOperationService().Debug();
            //Console.ReadLine();
        }
    }
    public class Student
    {
        public Student(int studentId, bool sex, String name, String address)
        {
            this.StudentId = studentId;
            this.Sex = sex;
            this.Name = name;
            this.Address = address;
        }
        public int StudentId { get; set; }
        public bool Sex { get; set; }
        public String Name { get; set; }
        public String Address { get; set; }

    }
    public class StudentListEquality : IEqualityComparer<Student>
    {
        public bool Equals(Student x, Student y)
        {
            return x.StudentId == y.StudentId;
        }

        public int GetHashCode(Student obj)
        {
            if (obj == null)
            {
                return 0;
            }
            return obj.ToString().GetHashCode();
        }
    }
}

结果

并集优先选oneStudents
交集优先选oneStudents
唯一集选择twoStudents顺序靠前的小新2，而不是小新22
如果调换顺序结果也会颠倒

  IList<Student> oneStudents = new List<Student>();
            oneStudents.Add(new Student(1, false, "小新1", "one"));
            oneStudents.Add(new Student(2, false, "小新2", "one"));

            IList<Student> twoStudents = new List<Student>();
            twoStudents.Add(new Student(2, false, "小新22", "two"));//这里吧小新22放前面了
            twoStudents.Add(new Student(2, false, "小新2", "two"));
          
            twoStudents.Add(new Student(3, false, "小新3", "two"));
　　　　　　　//交换顺序
            var bingji = twoStudents.Union(oneStudents, new StudentListEquality()).ToList();//并（全）集 
            var jiaoji = twoStudents.Intersect(oneStudents, new StudentListEquality()).ToList();//交集 
            var chaji = twoStudents.Except(oneStudents, new StudentListEquality()).ToList();//差集
            var weiyi = twoStudents.Distinct(new StudentListEquality()).ToList();

结果如下：