在带有实体版本 6 的 WCF 中使用“包含"语法时，复杂对象不会返回 [英] Complex Object won't return when using 'include' syntax in WCF with Entity Version 6

问题描述

好吧，这个让我很难过，因为我刚刚看到我的客户端在返回一个带有包含"的对象时基本上断开连接并终止.但是，它在没有跨 WCF SERVICE 的情况下工作正常.问题是我真的希望通过导航设置那些连接的对象.

Okay so this one has got me stumped as I just see that my client basically disconnects and terminates when returning an object with 'include'. However it works fine without that across a WCF SERVICE. The problem is that I really want those connected objects set up through navigation.

基本上代码是一个复杂的对象返回:

Basically the code is a complex object return:

public teCIF getCif(int aCifId)
        {
            using (CIFContainer context = GetCifContext())
            {
                var thing = context.teCIFs
                    .Include("Product_TYPE")
                    .FirstOrDefault(i => i.CIF_ID == aCifId);

                return thing;
            }
        }

现在奇怪的是，当我注释掉 include 语句时，这会正常工作.这就像通过 WCF 服务发送的复杂类型不喜欢包含语句，只是说:不，不会那样做".

Now the weird thing is that this will work JUST FINE when I comment out the include statement. It is like the complex type being sent over the WCF service does not like the include statement and just says: "nope, not going to do that".

为了参考我的复杂对象，我已经做了很多修改，因为它是从数据库中生成的 T4 对象(缩写):

For reference my Complex Object I have already hacked at quite a bit as it is a T4 generated object from a database (abbreviated):

[Serializable]
    public partial class teCIF
    {
        public int CIF_ID { get; set; }
        public string CUSTOMER_NAME { get; set; }
        public string SITE_NAME { get; set; }
        [System.Xml.Serialization.XmlIgnore]
        public int PRODUCT_TYPE_ID { get; set; }

        public virtual tlPRODUCT_TYPE Product_TYPE { get; set; }
    }

链接复杂项目的更新:

[Serializable]
public partial class tlPRODUCT_TYPE
{
    public tlPRODUCT_TYPE()
    {
        this.teCIFs = new HashSet<teCIF>();
    }

    [System.Xml.Serialization.XmlIgnore]
    public int PRODUCT_TYPE_ID { get; set; }
    public string VALUE { get; set; }

    [System.Xml.Serialization.XmlIgnore]
    public virtual ICollection<teCIF> teCIFs { get; set; }
}

我已尝试删除属性，但尚未弄乱 WCF 喜欢的数据成员"类型.我只是不明白为什么这不起作用，因为我发誓我在过去的实体版本 4 中使用复杂类型完成了此操作，其中导航属性与其他复杂类型相关.

I have tried removing attributes but have not yet messed with the 'data member' type that WCF likes. I just don't get why this does not work as I have sworn I have done this in the past Entity Version 4 with complex types with navigation properties related to other complex types.

推荐答案

好吧，实际上我从朋友那里得到了帮助，但认为这可能会为其他人提供帮助，所以我应该回答这个问题，因为它可能会帮助其他人.我必须添加一个自定义属性，我为它创建了一个确定循环引用的类.基本上，使用 WCF 时，指向导航的指针会以某种方式丢失，但在未连接到服务时很好.这并不好，因为我希望我的服务使用 WCF 托管方法，而不仅仅是客户端直接使用 Entity V6 调用.

Okay so I actually got help from a friend but figured that this could come up for others so I should answer the question as it may help someone else. I had to add a custom attribute that I make a class for that determines cyclic references. Basically the pointers to the navigation were somehow getting lost when using WCF, but were fine when not hooked up to a service. This is not good as I want my service to be hosting the methods using WCF, not just client calls directly using Entity V6.

    [ServiceContract]
    public interface ICifService
    {

        [OperationContract]
        [CyclicReferencesAware(true)]
        teCIF getCif(int aCifId);
    }

实现类的工作方式如下:

The implementation class works like this:

    using System;
    using System.ServiceModel;
    using System.ServiceModel.Description;
    using System.Runtime.Serialization;
    using System.Xml;
    using System.Collections.Generic;

    [AttributeUsage(AttributeTargets.Interface | AttributeTargets.Method)]
    public class CyclicReferencesAwareAttribute : Attribute, IContractBehavior, IOperationBehavior
    {
        private readonly bool _on = true;

        public CyclicReferencesAwareAttribute(bool on)
        {
            _on = on;
        }

        public bool On
        {
            get { return _on; }
        }

        #region IOperationBehavior Members

        void IOperationBehavior.AddBindingParameters(OperationDescription operationDescription, System.ServiceModel.Channels.BindingParameterCollection bindingParameters)
        {
        }

        void IOperationBehavior.ApplyClientBehavior(OperationDescription operationDescription, System.ServiceModel.Dispatcher.ClientOperation clientOperation)
        {
            CyclicReferencesAwareContractBehavior.ReplaceDataContractSerializerOperationBehavior(operationDescription, On);
        }

        void IOperationBehavior.ApplyDispatchBehavior(OperationDescription operationDescription, System.ServiceModel.Dispatcher.DispatchOperation dispatchOperation)
        {
            CyclicReferencesAwareContractBehavior.ReplaceDataContractSerializerOperationBehavior(operationDescription, On);
        }

        void IOperationBehavior.Validate(OperationDescription operationDescription)
        {
        }

        #endregion

        #region IContractBehavior Members

        void IContractBehavior.AddBindingParameters(ContractDescription contractDescription, ServiceEndpoint endpoint, System.ServiceModel.Channels.BindingParameterCollection bindingParameters)
        {
        }

        void IContractBehavior.ApplyClientBehavior(ContractDescription contractDescription, ServiceEndpoint endpoint, System.ServiceModel.Dispatcher.ClientRuntime clientRuntime)
        {
            CyclicReferencesAwareContractBehavior.ReplaceDataContractSerializerOperationBehaviors(contractDescription, On);
        }

        void IContractBehavior.ApplyDispatchBehavior(ContractDescription contractDescription, ServiceEndpoint endpoint, System.ServiceModel.Dispatcher.DispatchRuntime dispatchRuntime)
        {
            CyclicReferencesAwareContractBehavior.ReplaceDataContractSerializerOperationBehaviors(contractDescription, On);
        }

        void IContractBehavior.Validate(ContractDescription contractDescription, ServiceEndpoint endpoint)
        {
        }

        #endregion
    }

    public class CyclicReferencesAwareContractBehavior : IContractBehavior
    {
        private const int MaxItemsInObjectGraph = 2147483647;
        private const bool IgnoreExtensionDataObject = false;

        private bool _on;

        public CyclicReferencesAwareContractBehavior(bool on)
        {
            _on = on;
        }

        #region IContractBehavior Members

        public void AddBindingParameters(ContractDescription contractDescription, ServiceEndpoint endpoint, System.ServiceModel.Channels.BindingParameterCollection bindingParameters)
        {
        }

        public void ApplyClientBehavior(ContractDescription contractDescription, ServiceEndpoint endpoint, System.ServiceModel.Dispatcher.ClientRuntime clientRuntime)
        {
            ReplaceDataContractSerializerOperationBehaviors(contractDescription, _on);
        }

        public void ApplyDispatchBehavior(ContractDescription contractDescription, ServiceEndpoint endpoint, System.ServiceModel.Dispatcher.DispatchRuntime dispatchRuntime)
        {
            ReplaceDataContractSerializerOperationBehaviors(contractDescription, _on);
        }

        public void Validate(ContractDescription contractDescription, ServiceEndpoint endpoint)
        {
        }

        internal static void ReplaceDataContractSerializerOperationBehaviors(ContractDescription contractDescription, bool on)
        {
            foreach (var operation in contractDescription.Operations)
            {
                ReplaceDataContractSerializerOperationBehavior(operation, on);
            }
        }

        internal static void ReplaceDataContractSerializerOperationBehavior(OperationDescription operation, bool on)
        {
            if (operation.Behaviors.Remove(typeof(DataContractSerializerOperationBehavior)) || operation.Behaviors.Remove(typeof(ApplyCyclicDataContractSerializerOperationBehavior)))
            {
                operation.Behaviors.Add(new ApplyCyclicDataContractSerializerOperationBehavior(operation, MaxItemsInObjectGraph, IgnoreExtensionDataObject, on));
            }
        }
        #endregion
    }

    internal class ApplyCyclicDataContractSerializerOperationBehavior : DataContractSerializerOperationBehavior
    {
        private readonly int _maxItemsInObjectGraph;
        private readonly bool _ignoreExtensionDataObject;
        private readonly bool _preserveObjectReferences;

        public ApplyCyclicDataContractSerializerOperationBehavior(OperationDescription operationDescription, int maxItemsInObjectGraph, bool ignoreExtensionDataObject, bool preserveObjectReferences)
            : base(operationDescription)
        {
            _maxItemsInObjectGraph = maxItemsInObjectGraph;
            _ignoreExtensionDataObject = ignoreExtensionDataObject;
            _preserveObjectReferences = preserveObjectReferences;
        }

        public override XmlObjectSerializer CreateSerializer(Type type, string name, string ns, IList<Type> knownTypes)
        {
            return new DataContractSerializer(type, name, ns, knownTypes, _maxItemsInObjectGraph, _ignoreExtensionDataObject, _preserveObjectReferences, null /*dataContractSurrogate*/);
        }

        public override XmlObjectSerializer CreateSerializer(Type type, XmlDictionaryString name, XmlDictionaryString ns, IList<Type> knownTypes)
        {
            return new DataContractSerializer(type, name, ns, knownTypes, _maxItemsInObjectGraph, _ignoreExtensionDataObject, _preserveObjectReferences, null /*dataContractSurrogate*/);
        }
    }

一旦我将此属性应用于我的服务界面中的任何操作，它就适用于任何复杂类型.

Once I applied this attribute to any Operation in my interface for my service, it worked fine for any complex type.

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