WCF, channel factory, and exceptions

Question

Using vs2008, vb.net, C#, fw 3.5

I am consuming my service in my client

Service is hosted in IIS

Client(winforms MDI) is generated using svcutil using /l, /r, /ct, & /n switches

Service and client both use a MyEntities.dll

I am using nettcp with TransportWithMessageCredential I cache the proxy in the main form

if  Membership.ValidateUser(UsernameTextBox.Text, PasswordTextBox.Text)
    _proxy = new MyServiceClient
    _proxy.ClientCredentials.UserName.UserName = "username"
    _proxy.ClientCredentials.UserName.Password = "password"

I then pass the _proxy around to any child forms/plugins that need to use it ex

List(of Orders) =  _proxy.ChannelFactory.CreateChannel.GetOrders(customer)

Everything is working great but my questions are this:

What happens to the channels after the call? Are they magically disposed?

How could I monitor this, with a profiler?

Is there a way I can have error handling in one place, or do I need to place try/catch in every call like What is the best workaround for the WCF client `using` block issue?

try
{
    ...
    client.Close();
}
catch (CommunicationException e)
{
    ...
    client.Abort();
}
catch (TimeoutException e)
{
    ...
    client.Abort();
}
catch (Exception e)
{
    ...
    client.Abort();
    throw;
}

Could I subscribe to the _proxy.InnerChannel.Faulted and do that clean up there?

Regards

_Eric

Answer 1

I use to do two different things, depending on the use case:

• In a client scenario where I know only one instance of the channel is used at a time, I lazy-create a channel, and re-use the created instance. In case it is faulted, closed, or disposed, the channel is re-created.
• In scenarios where multiple channels can be requested at the same time, I think it is the best to do the exception handling dance. In order to avoid code bloat, you can centralize it into a method that accepts a delegate for the actual work that it done, so that it form a write-once exoskeleton around your payload code.