WCF + EF返回对象与FK

Question

我面临以下问题：我有ProductOrder类ProductId作为产品类的外键。当我调用下面的方法：

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

订单与产品相关的，所以我可以写这样的事：

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

，但是当它到达客户原来存在与产品没有关联这是null（仅包含ProductId）。看起来的DbContext我已经设置

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

在WCF服务端通过EF ProductOrder自动生成的类，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; } 
    } 

会发生什么，它失去与外键关联的表连接？

Answer 1

让您关系虚拟如示例：

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

通过转动你的关系virtual，实体框架将生成您ProductOrder类的代理将包含Product的参考。

，以确保它会工作，Product还必须包含对ProductOrder参考：

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

设置这些变量在您DbContext真：

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

在您WCF应用程序，添加以下班级，这将允许代理序列化：

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. 
    } 
} 

然后在你的ServiceContract接口您添加DataAnnotation[ApplyDataContractResolver]中的其他注释，如[OperationContract]右侧，上方返回一个实体的任何方法签名：

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