日志记录类（明确FileStreamDictionary等用法）

public static void Sample()
{
   Dictionary<string,string[]> dic = new Dictionary<string,string[]>();
   string[] zhejiang = {"aa","bb","cc"};  
   string[] shanghai = {“pudong","waitan"};
   dic.Add("ZJ", zhejiang);
   dic.Add("SH",shanghai);
}

public static void Sample3()
{
   Dictionary<string, string> stuList = new Dictionary<string,string>();
   Student stu=null;
   for(int i=0; i<3;i++)
   {
      stu = new Student();
      stu.Num = i.ToString();
      stu.Name = "StuName"+i.ToString();
      stuList.Add(i.ToString(),stu);
   }
}

public static void DicSample4()
{
       //1)普通调用
        Dictionary<int, String> dict = new Dictionary<int, String>();
        DictionaryExtensionMethodClass.TryAdd(dict, 1, "ZhangSan");
        DictionaryExtensionMethodClass.TryAdd(dict, 2, "WangWu");
        DictionaryExtensionMethodClass.AddOrPeplace(dict, 3, "WangWu");
        DictionaryExtensionMethodClass.AddOrPeplace(dict, 3, "ZhangWu");
        DictionaryExtensionMethodClass.TryAdd(dict, 2, "LiSi");

        //2)TryAdd 和 AddOrReplace 这两个方法具有较强自我描述能力，用起来很省心，而且也简单：
        dict.AddOrPeplace(20, "Orange");
        dict.TryAdd(21, "Banana");
        dict.TryAdd(22, "apple");

        //3)像Linq或jQuery一样连起来写   
        dict.TryAdd(10, "Bob")
              .TryAdd(11, "Tom")
              .AddOrPeplace(12, "Jom");
        //4) 获取值
        String F = "Ba";
        dict.TryGetValue(31, out F);
        Console.WriteLine("F : {0}",F);

        foreach (var dic in dict)
        {
            Console.WriteLine("Output : Key : {0}, Value : {1}", dic.Key, dic.Value);
        }
        //5)下面是使用GetValue获取值
        var v1 = dict.GetValue(111,null);
        var v2 = dict.GetValue(10,"abc");

        //6)批量添加
        var dict1 = new Dictionary<int,int>();
        dict1.AddOrPeplace(3, 3);
        dict1.AddOrPeplace(5, 5);

        var dict2 = new Dictionary<int, int>();
        dict2.AddOrPeplace(1, 1);
        dict2.AddOrPeplace(4, 4);
        dict2.AddRange(dict1, false);
  }
　　扩展方法所在的类
    public static class DictionaryExtensionMethodClass 
    {
        /// <summary>
        /// 尝试将键和值添加到字典中：如果不存在，才添加；存在，不添加也不抛导常
        /// </summary>
        public static Dictionary<TKey, TValue> TryAdd<TKey, TValue>(this Dictionary<TKey, TValue> dict, TKey key, TValue value)
        {
            if (dict.ContainsKey(key) == false)
                dict.Add(key, value);
            return dict;
        }

        /// <summary>
        /// 将键和值添加或替换到字典中：如果不存在，则添加；存在，则替换
        /// </summary>
        public static Dictionary<TKey, TValue> AddOrPeplace<TKey, TValue>(this Dictionary<TKey, TValue> dict, TKey key, TValue value)
        {
            dict[key] = value;
            return dict;
        }

        /// <summary>
        /// 获取与指定的键相关联的值，如果没有则返回输入的默认值
        /// </summary>
        public static TValue GetValue<TKey, TValue>(this Dictionary<TKey, TValue> dict, TKey key, TValue defaultValue)
        {
            return dict.ContainsKey(key)?dict[key] : defaultValue;
        }

        /// <summary>
        /// 向字典中批量添加键值对
        /// </summary>
        /// <param name="replaceExisted">如果已存在，是否替换</param>
        public static Dictionary<TKey, TValue> AddRange<TKey, TValue>(this Dictionary<TKey, TValue> dict, IEnumerable<KeyValuePair<TKey, TValue>> values, bool replaceExisted)
        {
            foreach (var item in values)
            {
                if (dict.ContainsKey(item.Key) == false || replaceExisted)
                    dict[item.Key] = item.Value;
            }
            return dict;
        }


    }