Question

我在EF Code First中使用Silverlight RIA服务嵌套对象，我能够在服务端获取数据，但是当我在客户端看到它时，子对象为空。你能指导我出错了。

[HasSelfValidation]
public class Batch
{

    public int BatchId { get; set; }
    public string BatchName { get; set; }
    [Include]
    [Composition]
    [Association("FK_Batch_BathSetItemSet", "BatchId", "BatchSetIdItemSetId")]
    public virtual ICollection<BatchSetItemSet> BatchSetItemSets { get; set; }
 }
public class BatchSetItemSet
{

    public int BatchSetIdItemSetId { get; set; }
    public int BatchId { get; set; }
    public Nullable<int> ItemSetId { get; set; }
    public string CreatedBy { get; set; }
    public  Batch Batch { get; set; }
     [Include]
     [Composition]
     [Association("FK_BathSetItemSet_ItemSet", "BatchSetIdItemSetId", "ItemSetId")]
    public  ItemSet ItemSet { get; set; }
}
public class ItemSet
{

    public int ItemSetId { get; set; }
    public int CustodianId { get; set; }
    public string ItemSetName { get; set; }
    public virtual ICollection<BatchSetItemSet> BatchSetItemSets { get; set; }
    [Include]
    [Composition]
    [Association("FK_ItemSet_Custodian", "ItemSetId", "CustodianId")]
    public virtual Custodian Custodian { get; set; }
}

和服务电话是：this.DbContext.Batches.Include("BatchSetItemSets.ItemSet.Custodian").Where(x => x.BatchId == batchId).SingleOrDefault();

Answer 1

您接近属性，但需要更改它们：

[HasSelfValidation]
public class Batch
{
    public int BatchId { get; set; }
    public string BatchName { get; set; }

    [Include]
    [Composition]
    [Association("FK_Batch_BathSetItemSet", "BatchId", "BatchId", IsForeignKey = false)]
    public virtual ICollection<BatchSetItemSet> BatchSetItemSets { get; set; }
 }

public class BatchSetItemSet
{
    public int BatchSetIdItemSetId { get; set; }
    public int BatchId { get; set; }
    public Nullable<int> ItemSetId { get; set; }
    public string CreatedBy { get; set; }

    [Include]
    [Association("FK_Batch_BathSetItemSet", "BatchId", "BatchId")]
    public Batch Batch { get; set; }

    [Include]
    [Association("FK_BathSetItemSet_ItemSet", "ItemSetId", "ItemSetId")]
    public ItemSet ItemSet { get; set; }
}

public class ItemSet
{
    public int ItemSetId { get; set; }
    public int CustodianId { get; set; }
    public string ItemSetName { get; set; }

    [Include]
    [Composition]
    [Association("FK_BathSetItemSet_ItemSet", "ItemSetId", "ItemSetId", IsForeignKey = false)]
    public virtual ICollection<BatchSetItemSet> BatchSetItemSets { get; set; }

    [Include]
    [Association("FK_ItemSet_Custodian", "CustodianId", "CustodianId")]
    public virtual Custodian Custodian { get; set; }
}

AssociationAttribute .ctor定义为：

AssociationAttribute(string name, string thisKey, string otherKey)

应配置为：

name：关系的每一端共享的唯一名称
thisKey：此对象上表示键或外键的属性名称
otherKey：另一个对象上表示键或外键的属性名称
IsForeignKey：AssociationAttribute上的一个属性，用于指示关系的这一端是主键还是外键。它默认为true（意味着此导航属性是外键）。通过将其设置为false，您向WCF RIA指示此对象包含主键。对于具有给定AssociationAttribute的所有name次使用，只允许一个IsForeignKey = false。否则，您将收到构建错误。

CODE FIRST EF RIA服务中客户端的嵌套对象为null

1 个答案: