using System;
using System.Collections;

namespace CollectionsApplication
{
 class Program
 {
 static void Main(string[] args)
 {
  Hashtable ht = new Hashtable();

  ht.Add("001", "Zara Ali");
  ht.Add("002", "Abida Rehman");
  ht.Add("003", "Joe Holzner");
  ht.Add("004", "Mausam Benazir Nur");
  ht.Add("005", "M. Amlan");
  ht.Add("006", "M. Arif");
  ht.Add("007", "Ritesh Saikia");

  if (ht.ContainsValue("Nuha Ali"))
  {
  Console.WriteLine("This student name is already in the list");
  }
  else
  {
  ht.Add("008", "Nuha Ali");
  }
  // 獲取鍵的集合 
  ICollection key = ht.Keys;

  foreach (string k in key)
  {
  Console.WriteLine(k + ": " + ht[k]);
  }
  Console.ReadKey();
 }
 }

using Systemusing System.Collections;namespace CollectionsApplication{ class Program {

　　　　private const string SavePath = @"C:\SavaFile\";
 public static List<string> YearStr = new List<string>() { };//存年份
 //存年份和編號
 public static Dictionary<string,List<string>> dic = new Dictionary<string,List<string>>() { };
 static void Main(string[] args)
 {
 　　 #region
  DirectoryInfo baseDir = new DirectoryInfo(SavePath);//讀取C:\SavaFile\路徑下的子目錄
　　　　　　DirectoryInfo[] dii = baseDir.GetDirectories();//存SaveFile文件夾子目錄
foreach (var item in dii) { dic.Add(item.Name,null); YearStr.Add(item.Name);//將SaveFile文件夾添加到YearStr集合中
  }
  DirectoryInfo dir; 
  foreach (var item in YearStr)
  {
   dir = new DirectoryInfo(SavePath+@"\"+item);　　　　　　　　　　//存SaveFile文件夾子目錄下的子目錄　　　　　　　　　　DirectoryInfo[] diis = dir.GetDirectories();
  List<string> Panlelst = new List<string>() { };//用來保存value
  foreach (var item2 in diis)
  {
   if (dic.ContainsKey(item))//如果Dictionary中包含了某個鍵
   {
   Panlelst.Add(item2.Name);//值添加值集合中
   dic[item] = Panlelst;//賦值到對應key中
   } 
  }
  }
  //遍歷字典
  foreach (KeyValuePair<string, List<string>> kvp in dic)
  {
  foreach (var item in kvp.Value)
  {
   Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, item);
  }  
  }
  Console.ReadLine(); 
  #endregion
 }
 }