[ApiController]
    [Route("[controller]")]
    public class PersonController : ControllerBase
    {
        [HttpGet("add")]          // 如果使用[controller]/[action]，则url变成Person/Add/add
        public ActionResult<int> Add(int i, int j)
        {
            return i + j;
        }

        [HttpGet("addTwo")]      // 如果使用[controller]/[action]，则url变成Person/Add2/addTwo
        public ActionResult<int> Add2(int i, int j)
        {
            return 2 * (i + j);
        }

        [HttpGet("div/{i}/{j}")]
        public ActionResult<int> Divide(int i, int j)
        {
            if (j == 0)
                return BadRequest("not support j == 0");  // ActionResult支持隐式转换，所以这里可以返回BadRequest

            return Ok(i / j);
        }

        [HttpGet("school/{schoolName}/class/{classNo}")]  // url的占位符和参数名相同，就不需要特别指定
        public Person Get(string schoolName, [FromRoute(Name = "classNo")] int classNum)
        {
            return new Person(1, $"{schoolName}_{classNum}_sss");
        }

        [HttpPost("new/{id}")]  // url的占位符和参数可以同时使用
        public ActionResult NewPerson(int id, [FromBody] Person p)
        {
            return Ok($"{p.Name} is added with id, {id}-{p.Id}");
        }
    }

    public class Person
    {
        public Person(int id, string name)
        {
            Id = id;
            Name = name;
        }

        public int Id { get; init; }
        public string Name { get; init; }
    }