我准备好了注释,但试着弄清楚如何使用我的代码使其可拖动: 
  
  
 
-(IBAction) updateLocation:(id)sender{
    MKCoordinateRegion newRegion;
    newRegion.center.latitude = mapView.userLocation.location.coordinate.latitude;
    newRegion.center.longitude = mapView.userLocation.location.coordinate.longitude;
    newRegion.span.latitudeDelta = 0.0004f;
    newRegion.span.longitudeDelta = 0.0004f;
    [mapView setRegion: newRegion animated: YES];
    CLLocationCoordinate2D coordinate;
    coordinate.latitude = mapView.userLocation.location.coordinate.latitude;
    coordinate.longitude = mapView.userLocation.location.coordinate.longitude;
    MKPointAnnotation *annotation = [[MKPointAnnotation alloc] init];
    [annotation setCoordinate: coordinate];
    [annotation setTitle: @"Your Car is parked here"];
    [annotation setSubtitle: @"Come here for pepsi"];
    [mapView addAnnotation: annotation];
    [mapView setZoomEnabled: YES];
    [mapView setScrollEnabled: YES];
} 
 提前致谢!
解决方法
 要使注释可拖动,请将注释视图的draggable属性设置为YES. 
  
 
        这通常在viewForAnnotation委托方法中完成.
例如:
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation
{
    if ([annotation isKindOfClass:[MKUserLocation class]])
        return nil;
    static Nsstring *reuseId = @"pin";
    MKPinAnnotationView *pav = (MKPinAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:reuseId];
    if (pav == nil)
    {
        pav = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:reuseId];
        pav.draggable = YES;
        pav.canShowCallout = YES;
    }
    else
    {
        pav.annotation = annotation;
    }
    return pav;
} 
 如果您需要在用户停止拖动并删除注释时进行处理,请参阅:
how to manage drag and drop for MKAnnotationView on IOS?
此外,您的注释对象(实现MKAnnotation的对象)应具有可设置的坐标属性.您正在使用MKPointAnnotation类,它实现了setCoordinate,以便已经处理了部分.