Ios 如何将自定义特性从Mapbox注释传递到其详图索引视图?
我将Ios 如何将自定义特性从Mapbox注释传递到其详图索引视图?,ios,swift,mapbox,Ios,Swift,Mapbox,我将MGLAnnotation子类化,以添加额外的属性var标记,如下所示: class MasterMapAnnotation: NSObject, MGLAnnotation { var coordinate: CLLocationCoordinate2D var title: String? var subtitle: String? var tags: String? init(coordinate: CLLocationCoordinate2
MGLAnnotation
子类化,以添加额外的属性var标记
,如下所示:
class MasterMapAnnotation: NSObject, MGLAnnotation {
var coordinate: CLLocationCoordinate2D
var title: String?
var subtitle: String?
var tags: String?
init(coordinate: CLLocationCoordinate2D, title: String?, subtitle: String?, tags: String?) {
self.coordinate = coordinate
self.title = title
self.subtitle = subtitle
self.tags = tags
}
}
以下是传递到地图中的注释:
let annotation = MasterMapAnnotation(coordinate: CLLocationCoordinate2D(latitude: 50.0, longitude: 50.0), title: "Numero Uno", subtitle: "Numero Uno subtitle", tags: "#tag1 #tag2")
mapView.addAnnotation(annotation)
mapView代理调用自定义详图索引视图:
func mapView(_ mapView: MGLMapView, calloutViewFor annotation: MGLAnnotation) -> MGLCalloutView? {
return MasterMapCalloutView(representedObject: annotation)
}
因此,在callout视图子类(下面)中,我如何访问这个新属性
标记
class MasterMapCalloutView: UIView, MGLCalloutView {
var representedObject: MGLAnnotation
let dismissesAutomatically: Bool = false
let isAnchoredToAnnotation: Bool = true
lazy var leftAccessoryView = UIView()
lazy var rightAccessoryView = UIView()
weak var delegate: MGLCalloutViewDelegate?
required init(representedObject: MGLAnnotation) {
self.representedObject = representedObject
super.init(frame: .zero)
}
required init?(coder decoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
// callout view delegate: present callout
func presentCallout(from rect: CGRect, in view: UIView, constrainedTo constrainedView: UIView, animated: Bool) {
if !representedObject.responds(to: #selector(getter: MGLAnnotation.title)) {
return
}
view.addSubview(self)
let title = representedObject.title
let tags = representedObject.tags // how to access this?
}
}
问题很明显,子类(
mastermapanotation
)拥有自定义的标记
属性,而不是它的超类(MGLAnnotation
),但我不知道如何(a)将representedObject设置为mastermapanotation
)或(b)只需访问MasterMapAnnotation
自定义属性,而无需重新配置协议。我可能遗漏了一些内容,但您只需检查是否可以将MGLAnnotation对象强制转换为MasterMapAnnotation:
guard let masterAnnotation : MasterMapAnnotation = representedObject as? MasterMapAnnotation else { return }
let tags : String? = masterAnnotation.tags
// etc
显然,除了使用guard之外,还有其他控制流量的方法,但我希望你能理解要点。不,你没有遗漏任何东西,我只是个新手。我不知道在哪里演出,我所有的尝试都失败了。@sconewolf不用担心,我们都需要从某个地方开始!再次感谢兄弟,你帮了我很多。快速提问帮助我更好地理解转换:你将
representedObject
向下转换到自定义子类(这对我来说非常有意义);您是否也可以将masterAnnotation
改为MGLAnnotation
?