change MKMapView's frame and center coordinate together smoothly in an animation

my code like this:

[UIView animateWithDuration:.3f animations:^{

mapView_.frame = CGRectMake(0,0, superView.frame.size.width, superView.frame.size.height);

MapAnnotation *ann = [baseAnn_ objectAtIndex:0];

[mapView_ setCenterCoordinate:ann.coordinate animated:NO];

}];

before animation the annotation is below the center of the mapView_, I want to change the mapView_'s frame while move the annotation to the center of the mapView_.

but the moving is not smooth, the annotation first move while the frame changing to a position still below the center, then move up to the center.

is there a way to make the annotation move direct to the final position, not first below is then move up?