ria 域服务正在回调中设置客户端属性

Question

我正在使用带有实体框架 4 和 silverlight 4 的 RIA 域服务。当我保存更改时，当服务调用返回时，会调用一些域服务函数，将值设置为“”，根本不应该更改。

我有两个实体

service.metadata.cs：

public partial class EntityA
{
    [Key]
    public Guid EntityA_Id { get; set; }

    public string Name { get; set; }

    public int EntityB_Id { get; set; }

    [Include]
    public EntityB entityB { get; set; }

}
public partial class EntityB
{
    [Required]
    public string Name { get; set; }

    public int EntityB_Id { get; set; }

    public EntityCollection<EntityA> entityA { get; set; }
}

在客户端，我在 EntityA 上有一个 Extra 属性来公开 EntityB 的 Name 属性。服务器端和域服务永远不需要知道这个属性，它仅适用于 GUI。

public partial class EntityA
{
    //Tags I have tried:
    //[IgnoreDataMember]
    //[XmlIgnore]
    //[Ignore]
    //[Exclude]
    public string NameOf_EntityB
    {
        get
        {
            return this.entityB == null ? string.Empty : this.entityB.Name;
        }
        set
        {
            this.entityB.Name = value;
        }
    }
}

如果我编辑实体 A 的名称并调用 serviceContext.SubmitChanges()，当调用返回某些域服务进程时，将设置 EntityA.NameOf_EntityB = ""; 因此，从用户的角度来看，他们保存一个值，而另一个值则为空。

我需要阻止这种情况发生。我尝试过各种数据属性，但它们要么在客户端不起作用，要么没有效果。

知道如何阻止域服务更改此值吗？

这是值更改之前的调用堆栈：

System.ServiceModel.DomainServices.Client!System.ServiceModel.DomainServices.Client.ObjectStateUtility.**ApplyValue**(object o, object value, System.Reflection.PropertyInfo propertyInfo, System.Collections.Generic.IDictionary<string,object> originalState, System.ServiceModel.DomainServices.Client.LoadBehavior loadBehavior) + 0x74 bytes   
System.ServiceModel.DomainServices.Client!System.ServiceModel.DomainServices.Client.ObjectStateUtility.ApplyState(object o, System.Collections.Generic.IDictionary<string,object> stateToApply, System.Collections.Generic.IDictionary<string,object> originalState, System.ServiceModel.DomainServices.Client.LoadBehavior loadBehavior) + 0x330 bytes 
System.ServiceModel.DomainServices.Client!System.ServiceModel.DomainServices.Client.Entity.ApplyState(System.Collections.Generic.IDictionary<string,object> entityStateToApply, System.ServiceModel.DomainServices.Client.LoadBehavior loadBehavior) + 0x68 bytes   
System.ServiceModel.DomainServices.Client!System.ServiceModel.DomainServices.Client.Entity.Merge(System.ServiceModel.DomainServices.Client.Entity otherEntity, System.ServiceModel.DomainServices.Client.LoadBehavior loadBehavior) + 0x5a bytes    
System.ServiceModel.DomainServices.Client!System.ServiceModel.DomainServices.Client.DomainContext.ApplyMemberSynchronizations(System.Collections.Generic.IEnumerable<System.ServiceModel.DomainServices.Client.ChangeSetEntry> changeSetResults) + 0x10e bytes  
System.ServiceModel.DomainServices.Client!System.ServiceModel.DomainServices.Client.DomainContext.ProcessSubmitResults(System.ServiceModel.DomainServices.Client.EntityChangeSet changeSet, System.Collections.Generic.IEnumerable<System.ServiceModel.DomainServices.Client.ChangeSetEntry> changeSetResults) + 0x262 bytes    
System.ServiceModel.DomainServices.Client!System.ServiceModel.DomainServices.Client.DomainContext.CompleteSubmitChanges(System.IAsyncResult asyncResult) + 0x1cb bytes  
System.ServiceModel.DomainServices.Client!System.ServiceModel.DomainServices.Client.DomainContext.SubmitChanges.AnonymousMethod__5() + 0x2e bytes   

编辑： 暂时找到了解决办法。在 ServiceContext.submitChanges() 调用的回调中，我可以调用 ServiceContext.RejectChanges() 来撤消对 EntityB 所做的更改。我不相信这个解决方案，因为在异步调用返回之前可能已经进行了其他更改，并且这些更改也将被拒绝。理想的解决方案是忽略该值并且根本不设置

Answer 1

您可能需要告诉 WCF RIA 有关您的实体的一些属性的更多信息：

public partial class EntityA
{
    [Key]
    public Guid EntityA_Id { get; set; }

    public string Name { get; set; }

    public int EntityB_Id { get; set; }

    [Include]
    [Association("EntityA-EntityB", "EntityA_Id", "EntityB_Id", IsForeignKey=false)]
    public EntityB entityB { get; set; }

}

public partial class EntityB
{
    [Required]
    public string Name { get; set; }

    [Key]
    public int EntityB_Id { get; set; }

    public Guid EntityA_Id { get; set; }

    [Include]
    [Association("EntityA-EntityB", "EntityA_Id", "EntityB_Id", IsForeignKey=true)]
    public EntityCollection<EntityA> entityA { get; set; }
}

Answer 2

这是我的解决方案：

private bool isExpanded = false;

public bool IsExpanded
{
    get { return isExpanded; }
    set
    {
        string stack = (new System.Diagnostics.StackTrace()).ToString();
        if (!stack.Contains("ObjectStateUtility.ApplyState") && isExpanded != value)
        {
            isExpanded = value;
            RaisePropertyChanged("IsExpanded");
        }
    }
}