使用其他程序集时调用启用 Silverlight 的 WCF 服务的异常

Question

一般说明

我正在从 Silverlight 应用程序调用启用 Silverlight 的 WCF 服务。我的服务查询数据库（SQL Server）并从那里返回值。问题是该服务使用了其他库来执行脏数据库工作，并且在尝试使用该服务时出现此异常：

例外

System.ServiceModel.CommunicationException was unhandled by user code   Message="An error occurred while trying to make a request to URI 'mysite/myservice.svc'. This could be due to attempting to access a service in a cross-domain way without a proper cross-domain policy in place, or a policy that is unsuitable for SOAP services. You may need to contact the owner of the service to publish a cross-domain policy file and to ensure it allows SOAP-related HTTP headers to be sent. This error may also be caused by using internal types in the web service proxy without using the InternalsVisibleToAttribute attribute. Please see the inner exception for more details."   StackTrace:
       at System.ServiceModel.AsyncResult.End[TAsyncResult](IAsyncResult result)
       at System.ServiceModel.Channels.ServiceChannel.SendAsyncResult.End(SendAsyncResult result)
       at System.ServiceModel.Channels.ServiceChannel.EndCall(String action, Object[] outs, IAsyncResult result)
       at System.ServiceModel.ClientBase`1.ChannelBase`1.EndInvoke(String methodName, Object[] args, IAsyncResult result)
       at ODP_Silverlight.ODP.WCFServices.PropertySetWcfServiceClient.PropertySetWcfServiceClientChannel.EndGetPropertySet(IAsyncResult result)
       at ODP_Silverlight.ODP.WCFServices.PropertySetWcfServiceClient.ODP_Silverlight.ODP.WCFServices.PropertySetWcfService.EndGetPropertySet(IAsyncResult result)
       at ODP_Silverlight.ODP.WCFServices.PropertySetWcfServiceClient.OnEndGetPropertySet(IAsyncResult result)
       at System.ServiceModel.ClientBase`1.OnAsyncCallCompleted(IAsyncResult result)   InnerException: System.Security.SecurityException
       Message=""
       StackTrace:
            at System.Net.Browser.AsyncHelper.BeginOnUI(SendOrPostCallback beginMethod, Object state)
            at System.Net.Browser.BrowserHttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
            at System.ServiceModel.Channels.HttpChannelFactory.HttpRequestChannel.HttpChannelAsyncRequest.CompleteGetResponse(IAsyncResult result)
       InnerException: System.Security.SecurityException
            Message="Security error."
            StackTrace:
                 at System.Net.Browser.BrowserHttpWebRequest.InternalEndGetResponse(IAsyncResult asyncResult)
                 at System.Net.Browser.BrowserHttpWebRequest.<>c__DisplayClass5.<EndGetResponse>b__4(Object sendState)
                 at System.Net.Browser.AsyncHelper.<>c__DisplayClass2.<BeginOnUI>b__0(Object sendState)
            InnerException:

更多信息

如果我从using 语句中删除“using mylibs”，而只返回一些带有几个数字的简单列表，那么服务就可以正常工作。

有什么见解吗？

Answer 1

使用 mylibs 不会调用任何代码。只有 mylibs 中的代码可以做到这一点。它似乎失败了。你应该测试一下。

请注意，由于此服务是在服务器上运行的（而不是在具有 SilverLight 的浏览器上），因此问题不可能是 SilverLight 权限。

Answer 2

您是否在 WCF 服务上实现了 ClientAccessPolicy.xml 和 CrossDomain.xml？与您收到的类似的 CommunicationException 可能是由缺少 ClientAccessPolicy.xml 文件或不允许您的 Silverlight 客户端访问服务引起的。