using System;

using System.Collections;

using System.Collections.Generic;

using System.Diagnostics;

using System.Linq;

namespace ConsoleTest

{

    class Program

    {

        class Test

        {

            public string Num = "";

        }

        static void Main(string[] args)

        {

            List<Test> listTest = new List<Test>();

            for (int i = ; i < ; i++)

            {

                listTest.Add(new Test { Num = i.ToString() });

            }

            int NumCount = ;

            //foreach (var list in listTest)

            //{

            //    NumCount++;

            //    if (listTest.Count < 20)

            //    {

            //        listTest.Add(new Test { Num = NumCount.ToString() });

            //    }

            //    Console.WriteLine(list.Num);

            //}//报错

            NumCount = ;

            for (int i = ; i < listTest.Count; i++)

            {

                NumCount++;

                if (listTest.Count < )

                {

                    listTest.Add(new Test { Num = NumCount.ToString() });

                }

                Console.WriteLine(listTest[i].Num);

            }

            Dictionary<string, string> dict = new Dictionary<string, string>();

            dict.Add("", "helo1");

            dict.Add("", "helo2");

            var keysList = new string[dict.Count];

            dict.Keys.CopyTo(keysList, );

            foreach (var key in keysList)

            {

                Console.WriteLine("key_  " + key.ToString() + ":" + dict[key]);

                dict.Remove(key);          //   Response.Write("key" + key.ToString() + ":" + dict[key]);

            }

            Console.WriteLine("AfterRemoved!=========================================");

            foreach (var dic in dict)

            {

                Console.WriteLine(dic.Key, dic.Value);

            }

            Console.WriteLine("dic AfterShow!=========================================");

            Dictionary<int, string> dict2 = new Dictionary<int, string>();

            dict2.Add(, "helo21");

            dict2.Add(, "helo22");

            var keysList2 = new int[dict2.Count];

            dict2.Keys.CopyTo(keysList2, );

            foreach (var key2 in keysList2)

            {

                Console.WriteLine("key_  " + key2.ToString() + ":" + dict2[key2]);

                dict.Remove(key2.ToString());          //   Response.Write("key" + key.ToString() + ":" + dict[key]);

            }

            Console.WriteLine("dict2 AfterRemoved!=========================================");

            foreach (var dic in dict)

            {

                Console.WriteLine(dic.Key, dic.Value);

            }

            Console.ReadLine();

            Console.Read();

        }

    }

}