List之Union(),Intersect(),Except() 即并集，交集，差集运算。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Sample2
{
class Program
{
static void Main(string[] args)
{
//List之Union(),Intersect(),Except() 即并集，交集，差集运算
IList<Student> Students1 = new List<Student>();
Students1.Add(new Student(1, false, "张三", "深圳"));
Students1.Add(new Student(2, false, "李四", "广州"));
Students1.Add(new Student(3, false, "王五", "珠海"));
Students1.Add(new Student(4, false, "赵六", "东莞"));

IList<Student> Students2 = new List<Student>();
Students2.Add(new Student(1, false, "张三", "深圳"));
Students2.Add(new Student(5, false, "李七", "广州"));
Students2.Add(new Student(6, false, "孙八", "深圳"));
Students2.Add(new Student(7, true, "赵燕", "深圳"));

//自定义比较规则
var bingji = Students1.Union(Students2, new StudentListEquality()).ToList();//并集（AB集合所有项）
var jiaoji = Students1.Intersect(Students2, new StudentListEquality()).ToList();//交集 (AB集合共同项)
var chaji = Students1.Except(Students2, new StudentListEquality()).ToList();//差集（A集合有,B没有）

Console.WriteLine("以下是并集的结果");
bingji.ForEach(x =>
{
Console.WriteLine(x.Id.ToString() + "    " + x.Sex.ToString() + "   " + x.Name.ToString() + " " + x.Address.ToString());

});

Console.WriteLine("以下是交集的结果");
jiaoji.ForEach(x =>
{
Console.WriteLine(x.Id.ToString() + "    " + x.Sex.ToString() + "   " + x.Name.ToString() + " " + x.Address.ToString());

});

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

});
Console.ReadKey();
}
}

public class Student
{
public Student(int id, bool sex, String name, String address)
{
this.Id = id;
this.Sex = sex;
this.Name = name;
this.Address = address;
}
public int Id { 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.Id == y.Id && x.Name == y.Name && x.Address == y.Address && x.Sex == y.Sex;
}
public int GetHashCode(Student obj)
{
return (obj == null) ? 0 : obj.ToString().GetHashCode();
}
}
}