Cant show my custom callout view

i wanna show custom callout view and center annotation view when user touch annotation pin,but there is some problem.When I called center map region and add my custom callout view in - (void)mapView:(MKMapView *)mapView
didSelectAnnotationView:(MKAnnotationView *)view u will remove all annotation view,
and my custom callout view is also removed.

Please help me thx
