初识c# 索引指示器

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

namespace ConsoleApplication1
{
    class Team
    {
        private int[] arr = new int[100];
        public int this[int index]   // Indexer declaration
        {
            get
            {
                // Check the index limits.
                //if (index < 0 || index >= 100)
                if ((index == 3)||(index==5))
                {
                    return arr[index];
                }
                else
                {
                    //其它除了3与５索引的元素，在调用方查询时全是777
                    return 777;
                }
            }
            set
            {
                //索引访问器的供值优先级高于调用此类对象的供值语句 Team test = new Team(); test[3] = 256;


                if (index == 3 || index == 5)
                {
                    arr[index] = 233444;
                }
            }
        }

    }
}

　　　　调用上述包含索引访问器的TEAM类

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

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            Team test = new Team();
            // 3与5号索引有数据，其它全是元素全是0
            注：此直接供值被team类的索引访问器set屏掉
            //即set优先极高于下述2行代码
            test[3] = 256;
            test[5] = 1024;
            for (int i = 0; i <= 10; i++)
            {
                //使用的是get索引访问器
                System.Console.WriteLine("Element #{0} = {1}", i, test[i]);
            }
            Console.ReadKey();
        }
    }
}

调试结果

Element #0 = 777 //对应get的else分支
Element #1 = 777
Element #2 = 777
Element #3 = 233444 //对应set部分
Element #4 = 777
Element #5 = 233444
Element #6 = 777
Element #7 = 777
Element #8 = 777
Element #9 = 777
Element #10 = 777

c#索引访问器再探_get_set之访问控制存取