c#属性（Property）

属性（property）是类（class）、结构（structure）和接口（interface）的命名（named）成员。类或结构中的成员变量或方法称为 域（field）。属性（property）是域（field）的扩展，且可使用相同的语法来访问。它们使用 访问器（accessors） 让私有域的值可被读写或操作。

该代码主要是帮助读者了解属性的用法，代码实现了添加属性值和根据添加的属性值进行筛选

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();

        }
    }
}

附加知识：

　　iformatprovider接口的引用，该接口用于格式化操作，当进行数字，日期时间，字符串匹配时，都会进行cultureinfo的操作，文中cultureinfo.createspecificculture("zh-cn")意为结果输出的是<简体,中国>