Size image pin annotation

问题

I put the personal image instead of the traditional red pin. When I open the map to display the pin, the image cover the entire map. Is there a maximum size of the pin image or how do I integrate something in the code to fit the size standard classic pin?

func mapView(mapView: MKMapView, viewForAnnotation annotation: MKAnnotation) -> MKAnnotationView? {
    if annotation is MKUserLocation {
        return nil
    }

    let annotationIdentifier = "SomeCustomIdentifier" // use something unique that functionally identifies the type of pin

    var annotationView: MKAnnotationView! = mapView.dequeueReusableAnnotationViewWithIdentifier(annotationIdentifier)

    if annotationView != nil {
        annotationView.annotation = annotation
    } else {
        annotationView = MKAnnotationView(annotation: annotation, reuseIdentifier: annotationIdentifier)

        annotationView.image = UIImage(named: "pin maps.png")

        annotationView.canShowCallout = true
        annotationView.calloutOffset = CGPointMake(-8, 0)

        annotationView.autoresizesSubviews = true
        annotationView.rightCalloutAccessoryView = UIButton(type: UIButtonType.DetailDisclosure) as UIView
    }

    return annotationView
}

回答1:

There is not a maximum size of the pin image. You need to resize UIImage.

    let annotationIdentifier = "SomeCustomIdentifier"
    var annotationView = mapView.dequeueReusableAnnotationView(withIdentifier: annotationIdentifier)
    if annotationView == nil {
        annotationView = MKAnnotationView(annotation: annotation, reuseIdentifier: annotationIdentifier)
        annotationView?.canShowCallout = true

        // Resize image
        let pinImage = UIImage(named: "pin maps.png")
        let size = CGSize(width: 50, height: 50)
        UIGraphicsBeginImageContext(size)
        pinImage!.draw(in: CGRect(x: 0, y: 0, width: size.width, height: size.height))
        let resizedImage = UIGraphicsGetImageFromCurrentImageContext()

        annotationView?.image = resizedImage

        let rightButton: AnyObject! = UIButton(type: UIButtonType.detailDisclosure)
        annotationView?.rightCalloutAccessoryView = rightButton as? UIView
    }
    else {
        annotationView?.annotation = annotation
    }

来源：https://stackoverflow.com/questions/33262759/size-image-pin-annotation