Visual studio breaks into an exception that is handled by IS with an unhandled exception dialog

Question

My code calls the WCF service, which is not working. Therefore, we must expect EndPointNotFoundException. The using statement attempts a Close()damaged connection that calls CommunicationObjectFaultedException, which is thrown. This exception falls into the catch try block surrounding the use block:

class Program
{
    static void Main()
    {
        try
        {
            using (ChannelFactory<IDummyService> unexistingSvc = new ChannelFactory<IDummyService>(new NetNamedPipeBinding(), "net.pipe://localhost/UnexistingService-" + Guid.NewGuid().ToString()))
            {
                using (IClientChannel chan = (unexistingSvc.CreateChannel() as IClientChannel))
                {
                    (chan as IDummyService)?.Echo("Hello");
                }
            }
        }
        catch (EndpointNotFoundException ex)
        {
            Console.WriteLine("Expected");
        }
        catch (CommunicationObjectFaultedException ex)
        {
            Console.WriteLine("Expected: caused by closing channel that has thrown EndPointNotFoundException");
        }
    }
}

Please note that the EndPoint service uses the new Guid, so it will never listen to the service.

IDummyService:

[ServiceContract]
interface IDummyService
{
    [OperationContract]
    string Echo(string e);
}

This causes the Visual Studio debugger (Visual Studio Professional 2017 15.4.1) to crash into the Excluded Unhandled popup: The exception that Visual Studio breaks System.ServiceModel.CommunicationObjectFaultedExceptioninto is where gets into the code.

, catch(CommunicationObjectFaultedException ex). LinqPad , , .

() using -block:

class Program
{
    static void Main()
    {
        try
        {
            using (ChannelFactory<IDummyService> unexistingSvc = new ChannelFactory<IDummyService>(new NetNamedPipeBinding(), "net.pipe://localhost/UnexistingService-" + Guid.NewGuid().ToString()))
            {
                IDummyService chan = null;
                try
                {
                    chan = unexistingSvc.CreateChannel();
                    chan.Echo("Hello");
                }
                catch (EndpointNotFoundException ex)
                {
                    Console.WriteLine($"Expected: {ex.Message}");
                }
                finally
                {
                    try
                    {
                        (chan as IClientChannel)?.Close();
                    }
                    catch (CommunicationObjectFaultedException ex)
                    {
                        Console.WriteLine($"Caused by Close: {ex.Message}");
                    }
                }
            }
        }
        catch (EndpointNotFoundException ex)
        {
            Console.WriteLine("Expected");
        }
        catch (CommunicationObjectFaultedException ex)
        {
            Console.WriteLine("Expected: caused by closing channel that has thrown EndPointNotFoundException");
        }
    }
}

Close.

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CommunicationObjectFaultedException async ?

Answer 1

Close() -ing a Faulted IClientChannel CommunicationObjectFaultedException:

public void Close(TimeSpan timeout)
{
    ...
    switch (originalState)
    {
        case CommunicationState.Created:
        case CommunicationState.Opening:
        case CommunicationState.Faulted:
            this.Abort();
            if (originalState == CommunicationState.Faulted)
            {
                throw TraceUtility.ThrowHelperError(this.CreateFaultedException(), Guid.Empty, this);
            }
            break;
        ...
    }
    ...
}

- (. CommunicationObject.Close(TimeSpan) # 299 .NET framework 4.7 ).

using -block try { ... } finally { Dispose(); } Dispose() Close(), . -, CreateChannel() RealProxy (src) RemotingServices.CreateTransparentProxy() , , .

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• Do using -block IClientChannel IClientChannel.State Close() -ing. WCF-` use`?

Answer 2

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