.net Core 2.0 Web API - Newtonsoft.Json.JsonSerializationException - IQueryable

Question

我有两个独立的 .net 核心应用程序，Web API 和客户端。我使用以下方法获取模型：

public IEnumerable<OhaMedication> GetOhaMedication()
{
    return _context.OhaMedication;
}

型号：

public class OhaMedication
{
    public int OhaMedicationId { get; set; }
    public string Phn { get; set; }
    public int OhaTypeId { get; set; }
    public int FrequencyId { get; set; }

    public MedFrequancy Frequency { get; set; }
    public OhaType OhaType { get; set; }
}

public class OhaType
{
    public OhaType()
    {
        OhaMedication = new HashSet<OhaMedication>();
    }

    public int OhaTypeId { get; set; }
    public string Name { get; set; }

    public ICollection<OhaMedication> OhaMedication { get; set; }
}


public class MedFrequancy
{
    public MedFrequancy()
    {
        OhaMedication = new HashSet<OhaMedication>();
    }

    public int FrequencyId { get; set; }
    public string Frequency { get; set; }

    public ICollection<OhaMedication> OhaMedication { get; set; }
}

在客户端中，我使用以下方法获取数据：

public IQueryable<OhaMedication> GetohaMedication()
{
    var dir = _session.GetString(SessionsKeys.Directory);
    bool connection = InternetConnection.Check(_webApiData.WebApiitems.Url);
    if (connection)
    {
        using (HttpClient client = new HttpClient())
        {
            client.BaseAddress = new Uri(_webApiData.WebApiitems.Url);
            MediaTypeWithQualityHeaderValue contentType =
                new MediaTypeWithQualityHeaderValue("application/json");
            client.DefaultRequestHeaders.Accept.Add(contentType);
            HttpResponseMessage response = client.GetAsync("/OhaMedications").Result;
            string stringData = response.Content.ReadAsStringAsync().Result;
            IQueryable<OhaMedication> data = JsonConvert.DeserializeObject<IQueryable<OhaMedication>>(stringData);
            return data;
        }
    }
    else
        return _context.OhaMedication;
}

我需要使用 IQueryable 来使用 include 如下：

var ohaMed = GetohaMedication().Where(x => x.Phn == phn).Include(o => o.Frequency)
.Include(o => o.OhaType).ToList();

我收到以下错误：

Newtonsoft.Json.JsonSerializationException: 'Cannot create and populate list type System.Linq.IQueryable`1[WebUI.Data.DataModels.OhaMedication]. Path '', line 1, position 1.'

Answer 1

它无法创建接口，因为不知道它实际应该使用哪种类型。尝试：

JsonConvert.DeserializeObject<List<OhaMedication>>(stringData).AsQueryable()

.net Core 2.0 Web API - Newtonsoft.Json.JsonSerializationException - IQueryable

.net Core 2.0 Web API - Newtonsoft.Json.JsonSerializationException - IQueryable

c#

json

entity-framework-core

asp.net-core-webapi