无法访问已释放的对象-wcf客户端

本文关键字：对象 -wcf 客户端 释放 访问 | 更新日期: 2023-09-27 18:30:03

我有一个WCF客户端遇到问题
我时不时地会遇到这样的异常：Cannot access a disposed object。这就是我打开连接的方式：

private static LeverateCrmServiceClient crm = null;
public static CrmServiceClient Get(string crmCertificateName)
        {
            if (crm != null)
            {
                crm.Close();
            }
            try 
            {
                crm = new LeverateCrmServiceClient("CrmServiceEndpoint");
                crm.ClientCredentials.ClientCertificate.SetCertificate(
                               StoreLocation.LocalMachine,
                               StoreName.My,
                               X509FindType.FindBySubjectName,
                               crmCertificateName);
            }
            catch (Exception e) 
            {
                log.Error("Cannot access CRM ", e);
                throw;
            }
            return crm;
        }

正如你所看到的，我每次都会关闭和重新打开连接。你认为问题出在哪里？

堆栈：

System.ServiceModel.Security.MessageSecurityException: Message security verification failed. ---> System.ObjectDisposedException: Cannot access a disposed object.
Object name: 'System.ServiceModel.Security.SymmetricSecurityProtocol'.
  at System.ServiceModel.Channels.CommunicationObject.ThrowIfClosedOrNotOpen()
  at System.ServiceModel.Security.MessageSecurityProtocol.VerifyIncomingMessage(Message& message, TimeSpan timeout, SecurityProtocolCorrelationState[] correlationStates)
  --- End of inner exception stack trace ---
Server stack trace:
  at System.ServiceModel.Security.MessageSecurityProtocol.VerifyIncomingMessage(Message& message, TimeSpan timeout, SecurityProtocolCorrelationState[] correlationStates)
  at System.ServiceModel.Channels.SecurityChannelFactory`1.SecurityRequestChannel.ProcessReply(Message reply, SecurityProtocolCorrelationState correlationState, TimeSpan timeout)
  at System.ServiceModel.Channels.SecurityChannelFactory`1.SecurityRequestChannel.Request(Message message, TimeSpan timeout)
  at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
  at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
  at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)
Exception rethrown at [0]:
  at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
  at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
  at Externals.CrmService.ICrmService.GetTradingPlatformAccountDetails(Guid ownerUserId, String organizationName, String businessUnitName, Guid tradingPlatformAccountId)
  at MyAppName.Models.ActionsMetadata.Trader.BuildTrader(Guid tradingPlatformAccountId) in C:'Users'X'Documents'Visual Studio 2010'Projects'MyAppName'MyAppName'Models'ActionsMetadata'Trader.cs:line 120
  at MyAppName.Models.ActionsMetadata.Trader.Login(String accountNumber, String password) in C:'Users'X'Documents'Visual Studio 2010'Projects'MyAppName'MyAppName'Models'ActionsMetadata'Trader.cs:line 48
  at MyAppName.Models.ActionsMetadata.Handlers.LoginHandler.Handle(StepHandlerWrapper wrapper) in C:'Users'X'Documents'Visual Studio 2010'Projects'MyAppName'MyAppName'Models'ActionsMetadata'Handlers'LoginHandler.cs:line 23
  at MyAppName.Models.ActionsMetadata.Handlers.HandlerInvoker.Invoke(IAction brokerAction, ActionStep actionStep, Dictionary`2 stepValues, HttpContext httpContext, BaseStepDataModel model) in C:'Users'X'Documents'Visual Studio 2010'Projects'MyAppName'MyAppName'Models'ActionsMetadata'Handlers'StepServerInoker.cs:line 42
  at MyAppName.Controllers.LoginController.Login(String step) in C:'Users'X'Documents'Visual Studio 2010'Projects'MyAppName'MyAppName'Controllers'LoginController.cs:line 35
  at lambda_method(Closure , ControllerBase , Object[] )
  at System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters)
  at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters)
  at System.Web.Mvc.ControllerActionInvoker.<>c__DisplayClass15.<InvokeActionMethodWithFilters>b__12()
  at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation)
  at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodWithFilters(ControllerContext controllerContext, IList`1 filters, ActionDescriptor actionDescriptor, IDictionary`2 parameters)
  at System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName)

无法访问已释放的对象-wcf客户端

根据堆栈跟踪，我假设您有一个ASP.NET MVC应用程序，其中包含一些代码，该应用程序调用Get方法来获取CrmServiceClient对象，然后继续调用该CrmServiceClient对象上的各种方法。例如，登录过程的一部分就是这样做的。

Get方法的工作方式是，每次调用它时，它都会首先关闭之前返回的CrmServiceClient对象（无论它是否仍在使用），然后创建并返回一个新对象。

想象一下，两个用户几乎同时尝试登录到您的应用程序，彼此相隔几毫秒。处理第一个用户登录的线程调用Get并获取其CrmServiceClient对象，然后一毫秒后，处理第二个用户的登录的线程呼叫Get，这导致第一个线程的CrmServiceClient对象关闭。然而，第一个线程仍在运行，现在当它试图调用其CrmServiceClient对象上的方法时，它会得到一个System.ObjectDisposedException: Cannot access a disposed object。

"正如你所看到的，我每次都会关闭和重新打开连接。"

当前Get方法中的代码不是实现这一点的好方法。相反，您应该让调用方负责关闭（或处置）CrmServiceClient对象，并且您可能应该将Get方法重命名为Open或Create来建议这样做。调用方应该使用using语句来确保对象被关闭/释放，而不管发生任何异常：

using (CrmServiceClient client = CrmServiceFactory.Get("my-crm-certificate"))
{
    client.Something();
    client.GetTradingPlatformAccountDetails();
    client.SomethingElse();
} // client is automatically closed at the end of the 'using' block
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