C# 简单的索引器程序

每次看c# 时 看到索引器那块就停下来了，看不太懂，也没感到什么实用的地，

正所谓无知啊，今天学习了个简单 索引器

主程序代码：

static void Main(string[] args)
        {
            ProgramGroup group = new ProgramGroup(); //实例化对象
            //Player[] name =new Player[2];//创建演员数组
            ////创建演员对象并给属性赋值
            //name[0]=new Player(); 
            //name[0].Name="甄子丹";
            //name[0].Role="叶问";
            ////创建演员对象并给属性赋值
            //name[1]=new Player();
            //name[1].Name="熊黛林";
            //name[1].Role="叶太太";
            //group.Players = name; //把数组赋值给对象的属性
            Console.WriteLine("演员阵容:");
            //for (int i = 0; i < group.Players.Length; i++)
            //{
            //    Console.WriteLine(group.Players[i].Name);//通过属性读取数组的值
            //}
            //group[0] = new Player();
            //group[0].Name = "甄子丹";
            //group[0].Role = "叶问";
            //group[1] = new Player();
            //group[1].Name = "熊黛林";
            //group[1].Role = "叶太太";
            //for (int i = 0; i < 2; i++)
            //{
            //    Console.WriteLine(group[i].Name);
            //}
            group.SetPlayers(); //调用对象的方法给字段赋值
            Console.WriteLine("甄子丹扮演" + group["甄子丹"].Role);
            Console.WriteLine("熊黛林扮演" + group["熊黛林"].Role);
            Console.ReadLine();
           
        }

剧组类代码

 class ProgramGroup //剧组类
    {
        //private Player[] players;  //演员数组字段

        //public Player[] Players  //演员数组属性
        //{
        //    get { return player; }
        //    set { player = value; }
        //}
        private Player[] players = new Player[2]; //演员数组字段
        //public Player this[int index]  //索引器，index是数组索引
        //{
        //    get { return players[index]; }
        //    set { players[index]=value;}
        //}
        public Player this[string name] //通过演员名称查找的索引器
        {
            get
            {
                int i = 0;
                for (; i < 2; i++) //循环查找演员
                {
                    if (players[i].Name == name)
                    {
                        break;
                    }
                }
                if (i == 2)
                {
                    return null; //没有找到返回空
                }
                else
                {
                    return players[i]; //找到返回数组中的演员元素
                }
            }
        }
        public void SetPlayers() //给数组赋值
        {
            players[0] = new Player();
            players[0].Name = "甄子丹";
            players[0].Role = "叶问";
            players[1] = new Player();
            players[1].Name = "熊黛林";
            players[1].Role = "叶太太";
        }
    }
    class Player //演员类
    {
        private string name; //演员名称字段

        public string Name  //演员名称属性
        {
            get { return name; }
            set { name = value; }
        }
        private string role;  //扮演角色字段

        public string Role  //扮演角色属性
        {
            get { return role; }
            set { role = value; }
        }
    }

感觉上面程序还是对索引器不太明白看下一个试试：

班级类：

    class Squad //班级类
    {
        string name; //班级名称

        public string Name
        {
            get { return name; }
            set { name = value; }
        }
        int count; //学生数量

        public int Count
        {
            get { return count; }
            set { count = value; }
        }
    }

年纪类：

 class Grade //年级类
    {
        string name; //年级名称

        public string Name
        {
            get { return name; }
            set { name = value; }
        }
        Squad[] squads = new Squad[2]; //班级数组
        public Squad this[int index]
        {
            set { squads[index] = value; }
            get { return squads[index]; }
        }
    }

主程序：

class Program
    {
        static void Main(string[] args)
        {
            Grade grade = new Grade(); //实例化对象
            grade.Name = "S1";
            grade[0] = new Squad(); //实例化数组元素对象
            grade[0].Name = "S1T100"; //调用索引器赋值
            grade[0].Count = 25;
            grade[1] = new Squad();
            grade[1].Name = "S1T101";
            grade[1].Count = 29;
            Console.WriteLine(grade.Name+"的班级有");
            Console.WriteLine(grade[0].Name+"里有"+grade[0].Count+"人");
            Console.WriteLine(grade[1].Name + "里有" + grade[1].Count + "人");
            Console.ReadLine();
        }
    }