WCF/C# Unable to catch EndpointNotFoundException

c#, error-handling, wcf

Solution

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.

Problem

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 when the server happens not to be there for whatever reason. I have tried a simple try/catch block to catch the specific error and the communication exception it derives from, and I've tried catching just Exception. None of these succeed in catching the exception, however I do get A first chance exception of type 'System.ServiceModel.EndpointNotFoundException' occurred in System.ServiceModel.dll in the output window when the client tries to open the service. Any ideas as to what I'm doing wrong?

Original source

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