动态加载的 xap 中的 WCF 服务调用失败

Question

我有一个容器/主 Silverlight 应用程序。此容器动态下载 xap，并调用下载的 xap 中的特定用户控件。其中一些用户控件调用服务器上承载的 WCF 服务。

当用户在下载的 xap 调用中控制 WCF 服务时，会出现以下错误：

System.InvalidOperationException was unhandled by user code
Message=Cannot find 'ServiceReferences.ClientConfig' in the .xap application 
package. This file is used to configure client proxies for web services, and 
allows the application to locate the services it needs. Either include this 
file in the application package, or modify your code to use a client proxy
constructor that specifies the service address and binding explicitly. Please
see inner exception for details.
StackTrace:
   at System.ServiceModel.Configuration.ServiceModelSectionGroup.
       GetSectionGroup()
   at System.ServiceModel.Configuration.ServiceModelSectionGroup.get_Current()
   at System.ServiceModel.Description.ConfigLoader.LookupChannel(
       String configurationName, String contractName, Boolean wildcard)
   at System.ServiceModel.Description.ConfigLoader.LoadChannelBehaviors(
       ServiceEndpoint serviceEndpoint, String configurationName)
   at System.ServiceModel.ChannelFactory.ApplyConfiguration(
       String configurationName)
   at System.ServiceModel.ChannelFactory.InitializeEndpoint(
       String configurationName, EndpointAddress address)
   at System.ServiceModel.ChannelFactory`1..ctor(
       String endpointConfigurationName, EndpointAddress remoteAddress)
   at System.ServiceModel.EndpointTrait`1.CreateSimplexFactory()
   at System.ServiceModel.EndpointTrait`1.CreateChannelFactory()
   at System.ServiceModel.ClientBase`1.CreateChannelFactoryRef(
       EndpointTrait`1 endpointTrait)
   at System.ServiceModel.ClientBase`1.InitializeChannelFactoryRef()
   at System.ServiceModel.ClientBase`1..ctor()
   at LoadableSilverlightApplication.MyServiceReference.MyServiceClient..ctor()
   at LoadableSilverlightApplication.Views.MyLoadablePage.textBlock2_Loaded(
       Object sender, RoutedEventArgs e)
   at MS.Internal.CoreInvokeHandler.InvokeEventHandler(
       Int32 typeIndex, Delegate handlerDelegate, Object sender, Object args)
   at MS.Internal.JoltHelper.FireEvent(
       IntPtr unmanagedObj, IntPtr unmanagedObjArgs, Int32 argsTypeIndex, 
       Int32 actualArgsTypeIndex, String eventName)
  InnerException: System.Xml.XmlException
      Message=Cannot find file 'ServiceReferences.ClientConfig' in the
          application xap package.
      LineNumber=0
      LinePosition=0
      StackTrace:
           at System.Xml.XmlXapResolver.GetEntity(
               Uri absoluteUri, String role, Type ofObjectToReturn)
           at System.Xml.XmlReaderSettings.CreateReader(
               String inputUri, XmlParserContext inputContext)
           at System.Xml.XmlReader.Create(
               String inputUri, XmlReaderSettings settings, 
               XmlParserContext inputContext)
           at System.ServiceModel.Configuration.ServiceModelSectionGroup.
               GetSectionGroup()
      InnerException:
          ...

异常告诉我ServiceReferences.ClientConfig不知何故不可见......即使它打包在下载的 XAP 中。

我确实看到一些帖子建议将ServiceReferences.ClientConfig与容器xap打包在一起，并且这种方法有效。但是，我不相信这是一个简洁的解决方案。

另一种选择是按照 http://weblogs.asp.net/manishdalal/archive/2009/02/23/silverlight-servicereferences-clientconfig-alternatives.aspx 中的建议自动执行ServiceReferences.ClientConfig。

有没有更好的解决方案解决这个问题？

Answer 1

WCF 将只在主应用程序 XAP 的 ClientConfig 文件中查找，而不在已下载的任何其他 XAP 中查找。 因此，您要么需要将配置放在主 XAP 中，要么需要自己提供配置，您链接的博客文章展示了一种方法。