MonoTouch, WCF, Large XML response, how to capture progress
===

I'm developing an app using MonoTouch and have to get some data from a 3rd party web service. I have a WCF binding to do such.

The particular web service method I am calling could potentially return an XML string in the range of several hundred megabytes, which could take a while to download to a mobile device.

I'm looking for some way to capture how many bytes have been read from the network at the system level, with the end-game being to display a progress indicator to the user. Is there some way I can achieve this using Behaviors? 

Note, I don't have any way to modify the web service code to return a Stream object, which is what most of the articles I have found require doing.

Any help or direction would be much appreciated. Thanks

As a last resort, I can always fall back on using an NSURLConnection to do this, instead of WCF, because I know there are NSURLConnectionDelegate methods to hook into that will provide this. I wanted to avoid NSURLConnection, so that I will be able to easily drop this code into an Android project in the future.