IOS Map地图内存释放

为了防止重复打开控制器，导致内存暴增 在dealloc方法释放

-(void)dealloc {
    [self.mapView removeFromSuperview];
    self.mapView.delegate = nil;
    self.mapView = nil;
}

地图缩放地图产生的内存这样释放

-(void)mapView:(MKMapView *)mapView regionDidChangeAnimated:(BOOL)animated{
    
    [_mapView removeFromSuperview];
    [self.view addSubview:mapView];
}