dynamic类型
dynamic类型在运行时做类型检查
可用于变量类型、方法参数和返回值类型
示例
dynamic person = new Student { Name = "张三", Age = 20 };
dynamic ViewBag{get ;set;}
dynamic d = new System.Dynamic.ExpandoObject();
d.Success = error ? "false" : "true";
d.Msg = msg;
d.Data = data;
return d;