Dictionary<int, string> test = new Dictionary<int, string> { };
            test.Add(0,"000");
            test.Add(4, "444");
            test.Add(2, "222");
            test.Add(6, "666");
 
            Dictionary<int, string> dic1Asc = test.OrderBy(o => o.Key).ToDictionary(o => o.Key, p => p.Value);
            
            
            Console.WriteLine("小到大排序");
            foreach(KeyValuePair<int,string> k in dic1Asc){
                Console.WriteLine("key:" +k.Key +" value:" + k.Value);
            }
 
            Console.WriteLine("大到小排序");
            Dictionary<int, string> dic1desc = test.OrderByDescending(o => o.Key).ToDictionary(o => o.Key, p => p.Value);
 
            foreach (KeyValuePair<int, string> k in dic1desc)
            {
                Console.WriteLine("key:" + k.Key + " value:" + k.Value);
            }