iphone - iOS4 code on iOS3 devices -

Whether iOS 4 specific code (such as Mkmapview overlays) is possible in an application, set up deployment targets using 4.0 3.0, and still do this work so long as the IOS4 code is not called on the 3.x device?

Now I'm trying to do this, and only calls the iOS 4 code if it supports the device, but I can not install GDB is angry. When I create the I33 device, I'll get it:

  dyld: Icon not found: _OBJC_CLASS _ $ _ MKOverlayView referenced: / var / mobile / application / 1EE8EC13-FA01-43CB- Expected in A617-9B5D268ECD13 /maps.app/maps: /System/Library/Frameworks/MapKit.framework/MapKit data formats are temporarily unavailable, try again after a 'release' (this time to call dlopen Not safe for.) Mi_cmd_stack_list_frames: Not enough frames in stack. Mi_cmd_stack_list_frames: Stacks do not have enough frames  

I want to run this application on 3.0 and up, and want to use the new MKMapView overlay on 4.0 devices.

Specifically, I am enforcing the tile image overlay code displayed on the WWDC, which uses the custom tile overlay which is MKOverlay Protocol, and a custom Tile Overwell view which MKOverlayView .

Try the weakness by adding the MapKit structure