Question

我试图通过我的odata WCF 服务获取对象的属性，但是当我在特定属性上使用$ expand时，它似乎是＆＃34; null＆＃34 ;。但是，在另一个属性中，我有该对象的Id（使用Entityframework），在那里你可以看到Id不是空的。

型号：

[Table("Approval"), DataContract, IgnoreProperties("Status", "Id")]
public class Approval : BaseEntity
{
    ...

    [DataMember]
    public Guid? ApproverId { get; set; }
    [DataMember, ForeignKey("ApproverId")]
    public virtual User Approver { get; set; }

    [DataMember]
    public virtual Request Request { get; set; }
}

[Table("Request"), DataContract, DataServiceKey("Id")]
public class Request : BaseEntity
{
    ...

    [DataMember]
    public Guid? LastModifiedById { get; set; }
    [DataMember, ForeignKey("LastModifiedById")]
    public virtual User LastModifiedBy { get; set; }

    [DataMember]
    public virtual Approval Approval { get; set; }

    [DataMember, Required]
    public Guid AbsenteeId { get; set; }
    [DataMember, ForeignKey("AbsenteeId")]
    public virtual User Absentee { get; set; }

    [DataMember, Required]
    public Guid AbsenceTypeId { get; set; }
    [DataMember, ForeignKey("AbsenceTypeId")]
    public virtual AbsenceType AbsenceType { get; set; }
}

odata服务电话：

http://<servername>/DataService.svc/Approvals?&$format=json&$expand=Request,Request/Absentee,Request/LastModifiedBy,Request/AbsenceType,Approver&$skip=0&$top=1

返回结果：

{
  "odata.metadata": "http://<servername>/DataService.svc/$metadata#Approvals",
  "value": [
    {
      "Approver": null,
      "Request": {
        "LastModifiedBy": null,
        "Absentee": null,
        "AbsenceType": null,
        ...
        "LastModifiedById": "6a1f8e79-99f5-e511-9444-0050568627d2",
        "AbsenteeId": "6a1f8e79-99f5-e511-9444-0050568627d2",
        "AbsenceTypeId": "fc7e8a5d-99f5-e511-9444-0050568627d2"
      },
      ...
      "ApproverId": null
    }
  ]
}

在这种情况下，值 - ＆gt;请求 - ＆gt; LastModifiedBy / Absentee / AbsenceType不应为空!!!!

有谁知道我错过了什么/做错了什么？

Odata $扩展属性返回null

0 个答案: