IEqualityComparer接口

時間 2019-12-07

標籤 iequalitycomparer 接口简体版

原文原文鏈接

IEqualityComparer<T>接口的對象的主要做用在於自定義判斷兩個對象是否相等。javascript

其中最經常使用的方法： bool Equals(T x, T y);html

實現該方法用於比較兩個對象是否相等。若是指定的對象相等，則爲 true；不然爲 false。java

代碼示例：git

    class Program
    {
        static void Main(string[] args)
        {
            People p1 = new People(1, "劉備", 23);
            People p2 = new People(1, "關羽", 22);
            People p3 = new People(1, "張飛", 21);
            List<People> listP1 = new List<People>();
            listP1.Add(p1);
            listP1.Add(p2);
            listP1.Add(p3);

            People p4 = new People(2, "趙雲", 23);
            People p5 = new People(2, "黃忠", 22);
            People p6 = new People(2, "馬超", 21);
            List<People> listP2 = new List<People>();
            listP2.Add(p4);
            listP2.Add(p5);
            listP2.Add(p6);

            Comparers c = new Comparers();
            bool b = listP1.SequenceEqual(listP2, c);   //只要集合中的對象年齡相等就視對象爲相等
            Console.WriteLine(b);   //輸出 True

            Console.ReadKey();
        }
    }

    public class Comparers : IEqualityComparer<People>
    {

        public bool Equals(People p1, People p2)
        {
            if (p1.Age == p2.Age)
            {
                return true;
            }
            return false;
        }

        public int GetHashCode(People obj)
        {
            throw new NotImplementedException();
        }
    }

    public class People
    {
        public People(int id, string name, int age)
        {
            this.Id = id;
            this.Name = name;
            this.Age = age;
        }

        public int Id
        {
            get;
            set;
        }

        public string Name
        {
            get;
            set;
        }

        public int Age
        {
            get;
            set;
        }
    }