This sample illustrates how to derive from NSInputStream and create subclass that is toll-free bridged to CFReadStream that can be used with NSMutableUrlRequest.
Note that the API required to implement a subclass of NSInputStream that is toll-free bridged to CFReadStream is considered private API by Apple, and may thus cause an app to be rejected from the AppStore.
This sample requires at least MonoTouch 5.3.4.
Rolf Bjarne Kvinge