小编典典

EF 4.1-代码优先-JSON循环引用序列化错误

c#

尽管据我所知我没有任何循环引用,但是我遇到了循环引用序列化错误。我正在从数据库中检索一组订单,并将它们作为JSON发送到客户端。所有代码如下所示。

这是错误:

错误

序列化类型为’System.Data.Entity.DynamicProxies.Order_83CECF2AA4DE38232F9077D4B26941AB96BC61230419EA8AC42C9100E6072812’的对象时,检测到循环引用。说明:执行当前Web请求期间发生未处理的异常。请查看堆栈跟踪,以获取有关错误及其在代码中起源的更多信息。

异常详细信息:System.InvalidOperationException:序列化类型为’System.Data.Entity.DynamicProxies.Order_83CECF2AA4DE38232F9077D4B26941AB96BC61230419EA8AC42C9100E6072812’的对象时,检测到循环引用。

源错误:

当前Web请求的执行期间生成了未处理的异常。可以使用下面的异常堆栈跟踪来标识有关异常的来源和位置的信息。

我的课程如下:

订购

public class Order
{
    [Key]
    public int OrderId { get; set; }

    public int PatientId { get; set; }
    public virtual Patient Patient { get; set; }

    public int CertificationPeriodId { get; set; }
    public virtual CertificationPeriod CertificationPeriod { get; set; }

    public int AgencyId { get; set; }
    public virtual Agency Agency { get; set; }

    public int PrimaryDiagnosisId { get; set; }
    public virtual Diagnosis PrimaryDiagnosis { get; set; }

    public int ApprovalStatusId { get; set; }
    public virtual OrderApprovalStatus ApprovalStatus { get; set; }

    public int ApproverId { get; set; }
    public virtual User Approver { get; set; }

    public int SubmitterId { get; set; }
    public virtual User Submitter { get; set; }

    public DateTime ApprovalDate { get; set; }

    public DateTime SubmittedDate { get; set; }
    public Boolean IsDeprecated { get; set; }
}

患者

public class Patient
{
    [Key]
    public int PatientId { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string MiddleInitial { get; set; }
    public bool IsMale;
    public DateTime DateOfBirth { get; set; }

    public int PatientAddressId { get; set; }
    public Address PatientAddress { get; set; }

    public bool IsDeprecated { get; set; }
}

认证期限

public class CertificationPeriod
{
    [Key]
    public int CertificationPeriodId { get; set; }
    public DateTime startDate { get; set; }
    public DateTime endDate { get; set; }
    public bool isDeprecated { get; set; }
}

机构

public class Agency
{
    [Key]
    public int AgencyId { get; set; }
    public string Name { get; set; }

    public int PatientAddressId { get; set; }
    public virtual Address Address { get; set; }
}

诊断

public class Diagnosis
{
    [Key]
    public int DiagnosisId { get; set; }
    public string Icd9Code { get; set; }
    public string Description { get; set; }
    public DateTime DateOfDiagnosis { get; set; }
    public string Onset { get; set; }
    public string Details { get; set; }
}

OrderApprovalStatus

public class OrderApprovalStatus
{
    [Key]
    public int OrderApprovalStatusId { get; set; }
    public string Status { get; set; }
}

用户

public class User
{
    [Key]
    public int UserId { get; set; }
    public string Login { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string NPI { get; set; }
    public string Email { get; set; }

}

注意:地址类别是编辑过程中的新添加

地址

public class Address
{
    [Key]
    public int AddressId { get; set; }
    public string StreetAddress { get; set; }
    public string City { get; set; }
    public string State { get; set; }
    public string Zip { get; set; }
    public string Phone { get; set; }
    public string Title { get; set; }
    public string Label { get; set; }
}

执行序列化的代码在这里:

摘自OrderController

    public ActionResult GetAll()
    {
        return Json(ppEFContext.Orders, JsonRequestBehavior.AllowGet);
    }

谢谢


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2020-05-19

共1个答案

小编典典

您可以尝试virtual从所有导航属性中删除关键字以禁用延迟加载和代理创建,然后使用快速加载来显式加载所需的对象图:

public ActionResult GetAll()
{
    return Json(ppEFContext.Orders
                           .Include(o => o.Patient)
                           .Include(o => o.Patient.PatientAddress)
                           .Include(o => o.CertificationPeriod)
                           .Include(o => o.Agency)
                           .Include(o => o.Agency.Address)
                           .Include(o => o.PrimaryDiagnosis)
                           .Include(o => o.ApprovalStatus)
                           .Include(o => o.Approver)
                           .Include(o => o.Submitter),
        JsonRequestBehavior.AllowGet);
}

参考您以前的文章,您的应用程序似乎也不依赖于延迟加载,因为您在那里引入了虚拟属性来延迟加载对象图,这可能会导致序列化麻烦。

编辑

不必virtual从导航属性中删除关键字(这将使模型完全无法进行延迟加载)。在代理受干扰的特定情况下(例如序列化),禁用代理创建(也将禁用延迟加载)就足够了:

ppEFContext.Configuration.ProxyCreationEnabled = false;

这仅对特定的上下文实例禁用代理创建ppEFContext

(我刚刚看过,@ WillC在这里已经提到过。请对此答案表示支持。)

2020-05-19