Using AsObservable to observe TPL Dataflow blocks without consuming messages

Question

I have a chain of TPL Dataflow blocks and would like to observe progress somewhere inside the system.

I am aware that I could just jam a TransformBlock

Answer 1

Try replacing:

obs.ForEachAsync(i => Debug.Print("progressBlock:" + i.ToString()));

with:

obs.Subscribe(i => Debug.Print("progressBlock:" + i.ToString()));

I'd imagine the ForEachAsync method isn't hooking in properly / it's firing, but something funky is going on with the async portion.