WCF + EF返回對象與FK

Question

我面臨以下問題：我有ProductOrder類ProductId作爲產品類的外鍵。當我調用下面的方法：

public IEnumerable<ProductOrder> GetOrders() 
{ 
     return OddzialDb.ProductOrders; 
} 

訂單與產品相關的，所以我可以寫這樣的事：

OddzialDb.ProductOrders.First().Product.Name; 

，但是當它到達客戶原來存在與產品沒有關聯這是null（僅包含ProductId）。看起來的DbContext我已經設置

base.Configuration.ProxyCreationEnabled = false; 
    base.Configuration.LazyLoadingEnabled = false; 

在WCF服務端通過EF ProductOrder自動生成的類，如下所示：

public partial class ProductOrder 
    { 
     public int Id { get; set; } 
     public Nullable<int> ProductId { get; set; } 
     public int Quantity { get; set; } 

     public virtual Product Product { get; set; } 
    } 

會發生什麼，它失去與外鍵關聯的表連接？

Answer 1

讓您關係虛擬如示例：

public class ProductOrder 
{ 
    public int Id { get; set; } 
    public virtual Product Product { get; set; } 
    public int ProductId { get; set; } 
} 

通過轉動你的關係virtual，實體框架將生成您ProductOrder類的代理將包含Product的參考。

，以確保它會工作，Product還必須包含對ProductOrder參考：

public class Product 
{ 
    public int Id { get; set; } 
    public string Name { get; set; } 
    public virtual ICollection<ProductOrder> ProductOrders { get; set; } 
} 

設置這些變量在您DbContext真：

Configuration.LazyLoadingEnabled = true; 
Configuration.ProxyCreationEnabled = true; 

在您WCF應用程序，添加以下班級，這將允許代理序列化：

public class ApplyDataContractResolverAttribute : Attribute, IOperationBehavior 
{ 
    public ApplyDataContractResolverAttribute() 
    { 
    } 

    public void AddBindingParameters(OperationDescription description, BindingParameterCollection parameters) 
    { 
    } 

    public void ApplyClientBehavior(OperationDescription description, System.ServiceModel.Dispatcher.ClientOperation proxy) 
    { 
     DataContractSerializerOperationBehavior dataContractSerializerOperationBehavior = 
      description.Behaviors.Find<DataContractSerializerOperationBehavior>(); 
     dataContractSerializerOperationBehavior.DataContractResolver = 
      new ProxyDataContractResolver(); 
    } 

    public void ApplyDispatchBehavior(OperationDescription description, System.ServiceModel.Dispatcher.DispatchOperation dispatch) 
    { 
     DataContractSerializerOperationBehavior dataContractSerializerOperationBehavior = 
      description.Behaviors.Find<DataContractSerializerOperationBehavior>(); 
     dataContractSerializerOperationBehavior.DataContractResolver = 
      new ProxyDataContractResolver(); 
    } 

    public void Validate(OperationDescription description) 
    { 
     // Do validation. 
    } 
} 

然後在你的ServiceContract接口您添加DataAnnotation[ApplyDataContractResolver]中的其他註釋，如[OperationContract]右側，上方返回一個實體的任何方法簽名：

[OperationContract] 
[ApplyDataContractResolver] 
[FaultContract(typeof(AtcWcfEntryNotFoundException))] 
Case GetSingleByCaseNumber(int number);