objective c - tabbarcontroller d'ont appear -

i' have problem. add tabbarcontroller based view project in appdelegate class added tabbarcontroller , code appdeegate.h

........... uitabbarcontroller * tab; @property (retain,nonatomic) iboutlet uitabbarcontroller * tab; appdelegate.m ........... @synthesize tab; [window addsubview:tabbarcontroller.view]; 

have checked connection in ib?