iOS - MKMapView - 可拖动注释

Question

我已经准备好注释了，但我想弄清楚如何用我的代码让它可以拖动:

-(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!

Answer 1

要使注释可拖动，请将注释 View 的 draggable 属性设置为YES。

这通常在 viewForAnnotation 委托(delegate)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;
}

如果需要在用户停止拖放注释时进行处理，请参见:
how to manage drag and drop for MKAnnotationView on IOS?

此外，您的注释对象(实现 MKAnnotation 的对象)应该有一个可设置的 coordinate 属性。您正在使用确实实现了 setCoordinate 的 MKPointAnnotation 类，因此该部分已经得到处理。