C#的索引器

using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;

namespace codeTest
{

    class Program
    {

        static void Main(string[] args)
        {
            IndexTest indexname = new IndexTest();
            indexname[] = "";
            indexname[] = "";
            indexname[] = "";
            indexname[] = "";
            indexname[] = "";
            indexname[] = "";
            indexname[] = "";
            indexname[] = "";
            indexname[] = "";
            indexname[] = "";
            for (int i = ; i < ; i++)
            {
                Console.WriteLine(indexname[i]);
            }

            Console.WriteLine(indexname[""]);
            Console.WriteLine(indexname[""]);
            Console.WriteLine(indexname[""]);
            IndexTest1 indextest1 = new IndexTest1();
            Console.WriteLine(indextest1[]);
            Console.WriteLine(indextest1[]);
            Console.WriteLine(indextest1[]);
            Console.ReadLine();
        }

        public class IndexTest
        {
            string[] indexName;
            public IndexTest()
            {
                indexName = new string[] { "", "", "", "", "", "", "", "", "", "" };
            }

            public string this[int index]
            {
                get
                {
                    string tmp;
                    if (index >=  && index <= )
                    {
                        tmp = indexName[index];
                    }
                    else
                    {
                        tmp = "";
                    }
                    return tmp;
                }
                set
                {
                    if (index >=  && index <= )
                    {
                        indexName[index] = value;
                    }
                }
            }

            public int this[string name]
            {
                get
                {
                    int index = ;
                    while (index < indexName.Length)
                    {
                        if (indexName[index] == name)
                        {
                            return index;
                        }
                        index++;
                    }

                    return -;
                }
            }

        }

        public interface IIndexTest
        {
            int this[int index]
            {
                get;
                set;
            }
        }

        public class IndexTest1 : IIndexTest
        {
            int[] array = new int[] { , , , ,  };

            public int this[int index]
            {
                get
                {
                    return array[index];
                }
                set
                {
                    array[index] = value;
                }
            }
        }

    }

}