/***
         * 验证初始化次数：static只初始化一次，无论多少用户访问，在内存中只有一份
         *              readonly每个线程初始化一次
         *              如果是接口中使用service方法，最好使用static 或者static readonly修饰符
         * 验证修饰符初始化顺序：static readonly-->static-->无修饰符-->readonly
         * */
        public object obj = new object();  //③
        public readonly object readonlyObj = new object();   //④
        public static readonly object staictReadonlyObj = new object(); //①
        public static object staictObj = new object();  //②


        // GET api/values
        public IEnumerable<string> Get()
        {
            var o = obj.GetType();
            var o0 = readonlyObj.GetType();
            var o1 = staictReadonlyObj.GetType();
            var o2 = staictObj.GetType();

            return new string[] { "value1", "value2" };
        }