WCF/C# Unable to catch EndpointNotFoundException

前端 未结 5 1342
北荒
北荒 2021-01-07 23:09

I have created a WCF service and client and it all works until it comes to catching errors. Specifically I am trying to catch the EndpointNotFoundException for

5条回答
  •  执念已碎
    2021-01-07 23:51

    I was able to replicate your issue and got interested (since I needed the same). I even researched a way to handle \ catch first chance exceptions but unfortunately it is not possible (for managed code) for .net framework 3.5 and below.

    On my case I always get a System.ServiceModel.CommunicationObjectFaultedException whenever something gets wrong on the service or whenever I access a down service. It turns out that c#'s using statement is the cause since behind the scene, the using statement always closes the service client instance even if an exception was already encountered (it doesn't jump to catch statement directly).

    What happens is that the original exception System.ServiceModel.EndpointNotFoundException will be replaced by the new exception System.ServiceModel.CommunicationObjectFaultedException whenever the using tries to close the service client instance.

    The solution i've made is to not use the using statement so that whenever an exception is encountered inside the try block it will instantly throw the exception to the catch blocks.

    Try to code something like:

    DashboardService.DashboardServiceClient svc = new Dashboard_WPF_Test.DashboardService.DashboardServiceClient();
    try
    {
        svc.GetChart(0);
    }
    catch (System.ServiceModel.EndpointNotFoundException ex)
    {
        //handle endpoint not found exception here
    }
    catch (Exception ex)
    {
        //general exception handler
    }
    finally
    {
        if (!svc.State.Equals(System.ServiceModel.CommunicationState.Faulted) && svc.State.Equals(System.ServiceModel.CommunicationState.Opened))
        svc.Close();
    }
    

    Instead of:

    try
    {
        using (DashboardService.DashboardServiceClient svc = new Dashboard_WPF_Test.DashboardService.DashboardServiceClient())
        {
            svc.GetChart(0);
        }
    }
    catch (System.ServiceModel.EndpointNotFoundException ex)
    {
        //handle endpoint not found exception here (I was never able to catch this type of exception using the using statement block)
    }
    catch (Exception ex)
    {
        //general exception handler
    }
    

    And you'll be able to catch the right exception then.

提交回复
热议问题