List<T>.Distinct()

class ListDistinctDemo
    {
        staticvoid Main(string[] args)
        {
            List<Person> personList =new List<Person>(){
                new Person(3),//重复数据
                new Person(3),
                new Person(2),
                new Person(1)
            };

            //使用匿名方法
            List<Person> delegateList = personList.Distinct(new Compare<Person>(
                delegate(Person x, Person y)
                {
                    if (null== x ||null== y) returnfalse;
                    return x.ID == y.ID;
                })).ToList();

            delegateList.ForEach(s => Console.WriteLine(s.ID));

            //使用 Lambda 表达式
            List<Person> lambdaList = personList.Distinct(new Compare<Person>(
                (x, y) => (null!= x &&null!= y) && (x.ID == y.ID))).ToList();

            lambdaList.ForEach(s => Console.WriteLine(s.ID));

            //排序
            personList.Sort((x, y) => x.ID.CompareTo(y.ID));
            personList.ForEach(s => Console.WriteLine(s.ID));

        }
    }
    publicclass Person
    {
        publicint ID { get; set; }
        publicstring Name { get; set; }
       
        public Person(int id)
        {
            this.ID = id;
        }
    }

    publicdelegatebool EqualsComparer<T>(T x, T y);

    publicclass Compare<T> : IEqualityComparer<T>
    {
        private EqualsComparer<T> _equalsComparer;

        public Compare(EqualsComparer<T> equalsComparer)
        {
            this._equalsComparer = equalsComparer;
        }

        publicbool Equals(T x, T y)
        {
            if (null!=this._equalsComparer)
                returnthis._equalsComparer(x, y);
            else
                returnfalse;
        }

        publicint GetHashCode(T obj)
        {
            return obj.ToString().GetHashCode();
        }
    }