C#初学--index

通过昨天goody的推荐，到叶子文文上面看了下C#的一些学习内容，感觉比较好，适合初学者。

我简单的过了遍，看到了索引的使用，感觉自己没什么概念，就学习了下。

下面是贴出来的代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace index
{
        class Worker
        {
                public string LastName;
                public string FirstName;
                public string MyBirth;

                public string this[int index]
                {
                        set
                        {
                                switch (index)
                                {
                                        case 0: LastName = value;
                                                break;
                                        case 1: FirstName = value;
                                                break;
                                        case 2: MyBirth = value;
                                                break;
                                        default:
                                                throw new ArgumentOutOfRangeException("index");
                                                break;
                                }
                        }
                        get
                        {
                                switch(index)
                                {
                                        case 0 : return LastName;
                                        case 1 : return FirstName;
                                        case 2 : return MyBirth;
                                        default :    
                                                throw new ArgumentOutOfRangeException("index");
                                                break;
                                }
                                        
                        }
                }
        }
        class Program
        {
                static void Main(string[] args)
                {
                        Worker a = new Worker();
                        Console.WriteLine("print the value:{0},{1},{2}",a[0],a[1],a[2]);
                        Console.WriteLine("please print your last name");
                        a[0] = Console.ReadLine();
                        Console.WriteLine("please print your first name");
                        a[1] = Console.ReadLine();
                        Console.WriteLine("please print your birthday");
                        a[2] = Console.ReadLine();
                        Console.WriteLine("Now,your name is {0},{1},and your birth is {2}",a[0],a[1],a[2]);

                }
        }
}

 

首先什么是索引呢？

书上说它是一组get和set访问器，我个人就直接这么认为就是获值或设值的概念。（可能是错误的啊，呵呵，理论太差，刚看的）。

 

怎样声明索引呢？

他的语法是如下：

要注意下面几点：a：索引没有名称，它是通过关键字this。

                                   b：参数列表在方括号里面。

                                   c：参数列表至少必须声明一个参数。

ReturnType this [type param1,...]
{
        get
                {
                        ...
                }
        set
                {
                        ...
                }
}