代码参考:

using System;

namespace FoodRobotDemo
{  
    public class FoodRobot
    {
        private int[] foodCountArr;
        private string[] foodNameArr;

        public FoodRobot()
        {
            foodCountArr = new int[3];
            foodNameArr = new string[3] {"航天","航空","宇航" };
        }
        public int this[string name]
        {
            get
            {
                int i = Array.IndexOf(foodNameArr, name);
                if (i != -1 && i >= 0 && i < 3)
                    return foodCountArr[i];
                else
                {
                    Console.WriteLine("读取操作有误,找不到{0}食品",name);
                    return -1;
                }
            }
            set
            {
                int i = Array.IndexOf(foodNameArr, name);
                if (i != -1)
                    foodCountArr[i] = value;
                else
                    Console.WriteLine("赋值操作有误,找不到{0}食品", name);
            }
        }      
       
    }


    class Program
    {
        static void Main(string[] args)
        {
            //多参数索引器和索引器重载          
            FoodRobot foodRobot = new FoodRobot();
            foodRobot["航天"] = 11;
            foodRobot["航空"] = 22;
            foodRobot["宇航"] = 33;
            foodRobot["行行"] = 44;
            Console.WriteLine(foodRobot["航天"]);
            Console.WriteLine(foodRobot["天天"]);
            Console.ReadKey();
        }
    }
}