To whom it may concern: My goal was to subclass IOBluetoothOBEXSession because I needed some unique instance variables and methods not contained in this class. There is one problem. The class method withIncomingRFCOMMChannel cannot be properly used by a subclass because it is defined as: + (IOBluetoothOBEXSession *)withIncomingRFCOMMChannel: (IOBluetoothRFCOMMChannel*) inChannel eventSelector:(SEL)inEventSelector selectorTarget:(id)inEventSelectorTarget refCon:(void *)inUserRefCon; With this definition, a subclass of IOBluetoothOBEXSession will always return the IOBluetoothOBEXSession type instead of the subclass type. It seems to me that the standard objC approach would have been to define this class method as follows: + (id)withIncomingRFCOMMChannel: (IOBluetoothRFCOMMChannel*) inChannel eventSelector:(SEL)inEventSelector selectorTarget:(id)inEventSelectorTarget refCon:(void *)inUserRefCon { id newInstance = [[[self class] alloc] init]; ....Do whatever you do to setup an OBEXSession... return [newInstance autorelease]; } This way when IOBluetoothOBEXSession is subclassed and the withIncomingRFCOMMChannel message is received by a subclass, the instance returned will be the same type as the subclass. Do you agree? Of course, I found another way to accomplish what I wanted to do. I would have liked my design better if the withIncomingRFCOMMChannel method were defined as mentioned. Regards, Paul Davis _______________________________________________ bluetooth-dev mailing list | bluetooth-dev@lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/bluetooth-dev Do not post admin requests to the list. They will be ignored.