public class LinkModel
{public stirng Href{get;set;}public stirng Rel{get;set;}public string Method{get;set;}public bool IsTemplated{get;set;}
}

public class DiaryModel
{//存储和模型相关的链接public ICollection<LinkModel> Links{get;set;}public DateTime CurrentDate{get;set;}
}public class Diary
{public int Id{get;set;}public DateTime CurrentDate{get;set;}
}

public class ModelFactory
{private UrlHelper _urlHelper;public ModelFactory(HttpRequestMessage request){_urlHelper = new UrlHelper(request);}//领域模型转换成视图模型public DiaryModel Create(Diary d){return new DiaryModel(){Links = new List<LinkModel>{CreateLink(_urlHelper.Link("Diaryis", new {diaryid=d.CurrentDate.ToString("yyyy-MM-dd")}),"self");},CurrentDate = d.CurrentDate}}public LinkModel CreateLink(string href, string rel, string method = "GET", bool isTemplated = false){return new LinkModel(){Href = href,Rel = rel,Method = method,IsTemplated = isTemplated}}//视图模型转换成领域模型public Diary Parse(DiaryModel model){try{var entity = new Diary();var selfLink = model.Links.Where(l => l.Rel == "self").FirstOrDefault();if(selfLink != null && !string.IsNullOrWhiteSpace(selfLink.Href)){//从Uri中取出主键var uri = new Uri(selfLink.Href);entity.Id = int.Parse(uri.Segments.Last());}entity.CurrentDate = model.CurrentDate;return entity;}catch(Exception ex){}}
}

//api/user/diaries
//api/user/diaries/2001-01-01
config.Routes.MapHttpRoute(name: "Diaries",routeTemplate: "api/user/diaries/{dairyid}",defaults: new {controller="diaries", diaryid=RouteParameter.Optional}
)

public abstract class BaseController : ApiController
{ICountingKsRepository _repo;ModelFactory _modelFactory;public BaseController(ICountingKsRepository repo){_repo = repo;//写在构造函数里的话有点迟，必须等实例化_modelFactory才有值//_modelFactory = new ModelFactory(this.Request);
    }protected ModelFactory TheModelFactory{get{if(_modelFactory == null){_modelFactory = new ModelFactory(this.Request, TheRepository);}return _modelFactory;}}protected ICountingsRepository TheRepoisitory{get{return _repo;}}
}

public class FoodsController : BaseController
{ICountingKsRepoisotry _repo;ModelFactory _modelFactory;public FoodsController(ICountingKsRepository repo) : base(repo){}const int PAGE_SIZE = 50;public object Get(bool includeMeasures = true, int page = 0){IQueryable<Food> query;if(includeMeausres){query = TheRepository.GetAllFoodsWithMeausres();}else{query = TheRepository.GetAllFoods();}//方便统计总数var baseQuery = query.OrderBy(f =>f.Description);//using System.Web.Http.Routingvar helper = new UrlHelper(Request);var links = new List<LinkModel>();if(page > 0){links.Add(TheModelFactory.CreateLink(helper.Link("Food", new {page = page - 1},"prevPage"));}if(page < totalPages - 1){links.Add(TheModelFactory.CreateLink(helper.Link("Food", new {page = page + 1},"nextPage"));}//把上一页和下一页的url保存下来//var prevUrl = page > 0 ? helper.Link("Food", new {page = page - 1}) : "";//var nextUrl = page > 0 ? helper.Link("Food", new {page  = page + 1}) : "";//输出总数var totalCount = baseQuery.Count();var totalPages = Math.Ceiling((double)totalCount/PAGE_SIZE);var result = baseQuery.Skip(PAGE_SIZE * page).Take(PAGE_SIZE).ToList().Select(f => TheModelFactory.FoodFromDomainToView(f));//方便客户端接收return new{TotalCount = totalCount,TotalPages = totalPages,Result = result，Links = links//PrevPageUrl = prevUrl,//NextPageUrl = nextUrl,
        }}public FoodModel Get(int foodid){return TheModelFactory.FoodFromDomainToView(TheRepository.GetFood(foodid));}
}

public class LinkModel
{public stirng Href{get;set;}public stirng Rel{get;set;}public string Method{get;set;}public bool IsTemplated{get;set;}
}

var jsonFormatter = config.Formatters.OfType<JsonMediaTypeFormatter>().FirstOrDefault();
jsonFormatter.SerializerSettings.ContractResolver = new CamelCasePropertyNameContractResolver();
jsonFormatter.SerializerSettings.Converts(new LinkModelConverter());

public class LinkModelConverter : JsonConverter
{public override bool CanConvert(Type objectType){return objectType.Equals(typeof(LinkModel));}public override object ReadJson(JsonReader reader, Type object){return reader.Value;}public override void WriteJson(JsonWriter wrtier, object value){var model = value as LinkModel;if(model != null){wirter.WriteStartObject();writer.WirteProeprtyName("href");writer.WriteValue(model.Href);writer.WriteProeprtyName("rel");writer.WriteValue(model.Rel);if(!model.Method.Equals("GET",StringComparison.ordinalIgnoreCase)){writer.WritePropertyName("method");writer.WriteValue(model.Method);}if(model.IsTemplated){writer.WriterPropertyName("isTemplated");writer.WriteValue(model.IsTemplated);}writer.WriteEndObject();}}
}