using System;

using System.Collections;

using System.Collections.Generic;

using System.Globalization;

using System.Linq;

using System.Text;

namespace 编码练习

{

    //创建一个类包含两个属性

    class People

    {

        public string Name { get; set; }

        public string Address { get; set; }

        public People(string name, string address)

        {

            this.Name = name;

            this.Address = address;

        }

    }

    //继承两个接口（枚举/格式化）

    class Peoples : IEnumerable

    {

        //创建一个对象列表

        private List<People> Lpeoples { get; set; }

        private StringBuilder Sbuilder { get; set; }

        public Peoples()

        {

            Lpeoples = new List<People>();

        }

        //创建一个可以往列表加属性实例的方法

        public void Add(People people)

        {

            Lpeoples.Add(people);

        }

        //获取对象值

        public IEnumerator GetEnumerator()

        {

            foreach (var p in Lpeoples)

            {

                yield return p;

            }

        }

        public override string ToString()

        {

            return GetContent(Lpeoples);

        }

        public string Tostring(string format)

        {

            return ToString(format, CultureInfo.CreateSpecificCulture("zh-CN"));

        }

        public string ToString(string format, IFormatProvider formatProvider)

        {

            IEnumerable<People> ps = Lpeoples;

            if (format.ToUpperInvariant() == "B")

            {

                ps = from p in Lpeoples where p.Address == "北京" select p;

            }

            else if (format.ToUpperInvariant() == "S")

            {

                ps = from p in Lpeoples where p.Address == "上海" select p;

            }

            return GetContent(ps);

        }

        //将数据连接到数组

        private string GetContent(IEnumerable<People> peoples)

        {

            Sbuilder = new StringBuilder();

            foreach (var p in peoples)

            {

                Sbuilder.AppendLine(string.Format("{0}{1}", p.Name, p.Address));

            }

            return Sbuilder.ToString();

        }

    }

    public class Start

    {

        public static void Main()

        {

            Peoples peoples = new Peoples()

            {new People("zhangsan","北京"),new People("lisi","上海"),new People("wangwu","北京"),new People("naliu","北京")};

            Console.WriteLine("本站会员有：");

            Console.WriteLine(peoples.ToString());

            Console.WriteLine("北京的会员有：");

            Console.WriteLine(peoples.Tostring("B"));

            Console.WriteLine("上海的会员有：");

            Console.WriteLine(peoples.Tostring("S"));

            Console.ReadLine();

        }

    }

}