WCF在多个客户端之间共享IClientMessageInspector实例

如何解决WCF在多个客户端之间共享IClientMessageInspector实例

| 通过以下标题为“ Centralized cookie management”（位于此处的http://megakemp.com/2009/02/06/managing-shared-cookies）标题下概述的方法进行WCF服务调用时，我正在管理共享的auth cookie。 -in-wcf / 我已经设置了自定义IClientMessageInspector，IEndpointBehavior，BehaviorExtensionElement作品。我的端点行为添加了一个消息检查器，如下所示：

public class MyEndpointBehavior : IEndpointBehavior
{
    public void AddBindingParameters(ServiceEndpoint endpoint,System.ServiceModel.Channels.BindingParameterCollection bindingParameters)
    {
    }
    public void ApplyClientBehavior(ServiceEndpoint endpoint,System.ServiceModel.Dispatcher.ClientRuntime clientRuntime)
    {
        // yuck.. Wish I had an instance of MyClientMessageInspector
        // (which has the auth cookie already) so I could just inject that
        // instance here instead of creating a new instance
        clientRuntime.MessageInspectors.Add(new MyClientMessageInspector());
    }
    public void ApplyDispatchBehavior(ServiceEndpoint endpoint,System.ServiceModel.Dispatcher.EndpointDispatcher endpointDispatcher)
    {
    }
    public void Validate(ServiceEndpoint endpoint)
    {
    }
}

一切都完美无瑕，但是当您要在多个客户端上共享Cookie时，此解决方案就会失效。因为ApplyDispatchBehavior()方法创建了一个新实例，所以其他任何客户端都不会获得该消息检查器实例，因此也不会获得身份验证票证。因此，然后我想到尝试创建一个自定义构造函数，以在其中注入实例，如下所示：

MyEndpointBehavior(MyClientMessageInspector msgInspector) { ... }

但是，WCF需要无参数的构造函数。 WCF在互联网上杂草丛生，可以进行依赖项注入，从而创建了IInstanceProvider，IServiceBehavior等。但是我不认为这就是我在这里要寻找的东西。谁能帮助我指引正确的方向？

解决方法

您只需要扩展概念，即可将cookie存储在消息检查器本身之外，以便消息检查器的所有实例共享同一存储。穷人的入门方法只是使用静态字段而不是实例字段。显然，如果您有多个线程，则在更新字段时需要提供并发性。如果将其外推到Cookie容器概念，然后确保与所有客户共享同一个容器，您甚至可以从中得到更多。共享容器可以通过获取客户端通道的ѭ8并向其添加属性来完成，然后您的行为会在检查消息并从中拉出cookie时寻找该属性。看起来有点像这样：应用逻辑

// Hold onto a static cookie container
public static CookieContainer MyCookieContainer;

// When instantiating the client add the cookie container to the channel parameters
MyClient client = new MyClient();
client.InnerChannel.GetProperty<ChannelParameterCollection>().Add(MyCookieContainer);

消息检查器逻辑

public void BeforeSendMessage(ref Message,IClientChannel clientChannel)
{
    // Find the cookie container for the current channel
    CookieContainer cookieContainer = clientChannel.GetProperty<ChannelParameterCollection>().Select(p => p as CookieContainer).Where(cc => cc != null).First();

    // ... use the cookie container to set header on outgoing context ...
}

, 您是正确的，IInstanceProvider对您的情况没有帮助-它仅用于提供服务实例。您不需要为行为设置无参数构造函数。您需要为config元素提供一个无参数的构造函数，并且此类可以使用一些依赖项注入类（请参见下文）来创建行为所需的适当的检查器类。

namespace ConsoleApplication4
{
    public class MyEndpointBehavior : IEndpointBehavior
    {
        IClientMessageInspector inspector;
        public MyEndpointBehavior(IClientMessageInspector inspector)
        {
            this.inspector = inspector;
        }

        public void AddBindingParameters(ServiceEndpoint endpoint,BindingParameterCollection bindingParameters)
        {
        }

        public void ApplyClientBehavior(ServiceEndpoint endpoint,ClientRuntime clientRuntime)
        {
            clientRuntime.MessageInspectors.Add(this.inspector);
        }

        public void ApplyDispatchBehavior(ServiceEndpoint endpoint,EndpointDispatcher endpointDispatcher)
        {
        }

        public void Validate(ServiceEndpoint endpoint)
        {
        }
    }
    public class MyEndpointBehaviorElement : BehaviorExtensionElement
    {
        public override Type BehaviorType
        {
            get { return typeof(MyEndpointBehavior); }
        }

        protected override object CreateBehavior()
        {
            return new MyEndpointBehavior(ClientInspectorFactory.GetClientInspector());
        }
    }
    public class MyClientInspector : IClientMessageInspector
    {
        public MyClientInspector()
        {
        }

        public void AfterReceiveReply(ref Message reply,object correlationState)
        {
            Console.WriteLine(\"AfterReceiveReply\");
        }

        public object BeforeSendRequest(ref Message request,IClientChannel channel)
        {
            Console.WriteLine(\"BeforeSendRequest\");
            return null;
        }
    }
    public static class ClientInspectorFactory
    {
        static IClientMessageInspector instance;
        public static IClientMessageInspector GetClientInspector()
        {
            if (instance == null)
            {
                instance = new MyClientInspector();
            }

            return instance;
        }
    }
    [ServiceContract]
    public interface ITest
    {
        [OperationContract]
        int Add(int x,int y);
    }
    public class Service : ITest
    {
        public int Add(int x,int y) { return x + y; }
    }
    class Program
    {
        static void Main(string[] args)
        {
            ServiceHost host = new ServiceHost(typeof(Service));
            host.Open();
            Console.WriteLine(\"Host opened\");

            ChannelFactory<ITest> factory = new ChannelFactory<ITest>(\"client1\");
            ITest proxy = factory.CreateChannel();
            Console.WriteLine(proxy.Add(3,4));
            ((IClientChannel)proxy).Close();
            factory.Close();

            factory = new ChannelFactory<ITest>(\"client2\");
            proxy = factory.CreateChannel();
            Console.WriteLine(proxy.Add(5,8));
            ((IClientChannel)proxy).Close();
            factory.Close();

            host.Close();
        }
    }
}

, 我喜欢@carlosfigueira和@drew提供的答案，但最终我想出了一个略有不同的方法。我选择通过编程来配置IEndpointBehavior，而不是通过config。使事情变得简单得多。我将端点行为更改为存储客户端消息检查器，如下所示：

public class MyEndpointBehavior : IEndpointBehavior
{
    private MyClientMessageInspector_myClientMessageInspector;

    public MyClientMessageInspector MyClientMessageInspector
    {
        get
        {
            if (_myClientMessageInspector == null)
            {
                _myClientMessageInspector = new MyClientMessageInspector();
            }
            return _myClientMessageInspector;
         }
    }
    public void AddBindingParameters(ServiceEndpoint endpoint,System.ServiceModel.Channels.BindingParameterCollection bindingParameters)
    {
    }
    public void ApplyClientBehavior(ServiceEndpoint endpoint,System.ServiceModel.Dispatcher.ClientRuntime clientRuntime)
    {
        clientRuntime.MessageInspectors.Add(MyClientMessageInspector);
    }
public void ApplyDispatchBehavior(ServiceEndpoint endpoint,System.ServiceModel.Dispatcher.EndpointDispatcher endpointDispatcher)
    {
    }
    public void Validate(ServiceEndpoint endpoint)
    {
    }
}

然后，我仅在客户端之间共享此行为，如下所示：

var behavior = new MyEndpointBehavior();
client1.Endpoint.Behaviors.Add(behavior);
client2.Endpoint.Behaviors.Add(behavior);

现在，两个客户端将共享相同的身份验证cookie。

WCF在多个客户端之间共享IClientMessageInspector实例

如何解决WCF在多个客户端之间共享IClientMessageInspector实例

解决方法

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