class Program
    {
        static void Main(string[] args)
        {
            chinnease china = new chinnease();
                        Console.WriteLine(china);
            Console.ReadKey();
        }
    }
     public class chinnease     {
        public override string ToString()
        {
            return "我是子类tostring";
        }
          }我想问下Console.WriteLine(china);这句代码,我没写方法名,怎么会自动调用chinnease类里的     ToString方法