static void Main(string[] args)
        {
            Dictionary<int, int> _dic = new Dictionary<int, int>();

            _dic.Add(3, 3);
            _dic.Add(1, 1);
            _dic.Add(2, 2);
            _dic.Add(6, 6);

            Console.WrITeLine("未经排序:");foreach (VAR k in _dic)
            {
                Console.WriteLine(k.Key + "   " + k.Value);
            }var dic_sort = From dic in _dic orderby dic.Key select dic;
            Console.WriteLine("未经处理:");foreach (var k in dic_sort)
            {
                Console.WriteLine(k.Key + "   " + k.Value);
            }

            Console.WriteLine("经过删除添加处理:");
            _dic.Remove(2);
            _dic.Add(4, 4);foreach (var k in _dic)
            {
                Console.WriteLine(k.Key + "   " + k.Value);
            }

            Console.Read();
        }