C# WebApi重构选择Linq

Question

我目前正在 Visual Studio 2015 中编写 C# Web Api。我实际上复制粘贴了很多代码。

public class APIController : ApiController
{
    [HttpGet]
    [Route("api/drones")]
    public HttpResponseMessage getDrones()
    {
        var drones = db.drones.Select(d => new DroneDTO
        {
            iddrones = d.iddrones,
            //more stuff
        });
        HttpResponseMessage res = Request.CreateResponse(HttpStatusCode.OK, drones);
        return res;
    }

    [HttpGet]
    [Route("api/drones/{id}")]
    public HttpResponseMessage getDrones(int id)
    {
        var drone = db.drones.Select(d => new DroneDTO
        {
            iddrones = d.iddrones,
            //more stuff
        }).Where(drones => drones.iddrones == id);
        HttpResponseMessage res = Request.CreateResponse(HttpStatusCode.OK, drone);
        return res;
    }
}

我应该如何重构它？起初我想将 var 移动到类成员，但这似乎是不允许的。

Answer 1

我会制作一个适用于 IQueryable<T> 的 DTO 工厂方法然后这两个函数将只负责创建正确的查询。

当您将这些函数设为异步时，这将使您在未来处于更好的位置。

    public class DroneDTO
    {
        public int Id { get; set; }
        public static IEnumerable<DroneDTO> CreateFromQuery(IQueryable<Drone> query)
        {
            return query.Select(r=> new DroneDTO
            {
                Id = r.Id
            });
        }
    }


    public class APIController : ApiController
    {
        [HttpGet]
        [Route("api/drones")]
        public HttpResponseMessage getDrones()
        {
            var drones = DroneDTO.CreateFromQuery(db.drones);

            HttpResponseMessage res = Request.CreateResponse(HttpStatusCode.OK, drones);
            return res;
        }

        [HttpGet]
        [Route("api/drones/{id}")]
        public HttpResponseMessage getDrones(int id)
        {
            var drone = DroneDTO.CreateFromQuery(db.drones.Where(d => d.iddrone == id));

            HttpResponseMessage res = Request.CreateResponse(HttpStatusCode.OK, drone);
            return res;
        }
    }