如何从C#Web API DbSet获取实际对象?

时间:2013-07-09 21:02:08

标签: c# json entity-framework rest asp.net-web-api

我正在尝试获取自上次检查后已添加到框(数据库)中的“最近”甜甜圈列表。我很胖,想要一些美味的noms。问题:服务器给我的JSON充满了$ id和$ refs,所以我的列表最终成为一个对象,其余为null(因为response.Content.ReadAsAsync不处理引用)。

请帮忙。我只想要一些直接的甜甜圈对象男人。这些$ ref icing或$ id填充都没有。

我的服务器端控制器:

public class DonutController : ApiController
{
    private DonutEntities db = new DonutEntities();

    // GET api/PackageEvent/since/{datetime}
    public IEnumerable<Donut> GetDonutsSince([FromUri] String datetime) {
        List<Donut> donuts = null;
        DateTime dt = DateTime.Parse(datetime);

        //return db.Donuts.Where(d => d.When > dt).AsEnumerable();

        String sql = @"
            SELECT *
            FROM Donuts
            WHERE [Donuts].[When] > CAST(@datetime AS DATETIME)
        ";

        object[] parameters = new object[] {
            new SqlParameter("@datetime", DateTime.Parse(datetime).ToString(CultureInfo.InvariantCulture))
        };

        List<Donut> results = db.Donuts.SqlQuery(sql, parameters).ToList();
        if (results.Any()) {
            donuts = results;
        }

        return donuts.AsEnumerable();
    }
}

我的客户端请求方法:

    public static IEnumerable<Donut> GetDonutsSince(DateTime dt) {
        HttpClient api = new HttpClient { BaseAddress = new Uri("http://localhost:55174/api/") };
        api.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

        String url = "Donut/since?datetime=" + dt;
        HttpResponseMessage response = api.GetAsync(url).Result;

        Console.WriteLine(response.Content.ReadAsStringAsync().Result);
        // outputs the raw json with $ids and $refs

        IEnumerable<Donut> donuts = response.Content.ReadAsAsync<IEnumerable<Donut>>().Result;

        return donuts;
    }

1 个答案:

答案 0 :(得分:0)

事实证明,解决方案是使用Json.NET。它处理$ id和$ ref属性,并实际创建一个填充了对象的列表。

新的客户端请求方法:

public static IEnumerable<Donut> GetDonutsSince(DateTime dt) {
    HttpClient api = new HttpClient { BaseAddress = new Uri("http://localhost:55174/api/") };
    api.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

    String url = "Donut/since?datetime=" + dt;
    HttpResponseMessage response = api.GetAsync(url).Result;
    String responseContent = response.Content.ReadAsStringAsync().Result;

    IEnumerable<Donut> events = JsonConvert.DeserializeObject<IEnumerable<Donut>>(responseContent);

    return donuts;
}