how to show multiple lines in MKAnnotation with autolayout?

Question

i am using mapkit how i can multiple line in MKAnnotation view.

Every annotation there has title and subtitle. how i show sub title with

Answer 1

5 steps

I created a label and added it to the annotationView?.detailCalloutAccessoryView property (step 5). I also set the label's text to the annotation.subtitle text (step 2 & step 4) and .numberOfLines = 0

Steps are in the comments above the code

func mapView(mapView: MKMapView, viewForAnnotation annotation: MKAnnotation) -> MKAnnotationView? {

    if annotation.isKindOfClass(MKUserLocation) {
        return nil
    }

    let reuseIdentifier = "reuseIdentifier"

    var annotationView = mapView.mapView.dequeueReusableAnnotationView(withIdentifier: reuseIdentifier) as? MKPinAnnotationView

    if annotationView == nil {

        annotationView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: reuseIdentifier)

        // 1. set the annotationView's canShowCallout property to true
        annotationView?.canShowCallout = true

        // 2. get the subtitle text from the annontation's subtitle property
        let subtitleText = annotation.subtitle ?? "you have no subtitle"

        // 3. create a label for the subtitle text
        let subtitleLabel = UILabel()
        subtitleLabel.translatesAutoresizingMaskIntoConstraints = false

        // 4. set the subtitle's text to the label's text property and number of lines to 0
        subtitleLabel.text = subtitleText
        subtitleLabel.numberOfLines = 0

        // 5. set the annotation's detailCalloutAccessoryView property to the subtitleLabel
        annotationView?.detailCalloutAccessoryView = subtitleLabel

    } else {
        annotationView!.annotation = annotation
    }

    return annotationView
}