[英]iOS Swift MapKit why MKPointAnnotation is draggable while a class that conforms MKAnnotation is not
i have a class that is a subclass of NSManagedObject that conform to MKAnnotation
and then i use that in a MapView
that dequeues some locations from CoreData
我有一个类,它是符合
MKAnnotation
的NSManagedObject的子类,然后在MapView
中使用它从CoreData
某些位置出CoreData
class Location: NSManagedObject , MKAnnotation {
var coordinate : CLLocationCoordinate2D {
return CLLocationCoordinate2D(latitude: Double(self.latitude), longitude: Double(self.longitude))
}
var title: String? {
return self.name
}
var subtitle: String? {
return self.category
}
}
i then add the fetched objects to the MapView
as MKAnnotation
like that 然后我像这样将获取的对象作为
MKAnnotation
添加到MapView
中
self.MapView.addAnnotations(self.locations)
and in the viewForAnnotation
i made a subclass of MKAnnotationView
that has a rounded imageView 在
viewForAnnotation
我制作了MKAnnotationView
的子类,该子类具有舍入的MKAnnotationView
class AMKAnnotationView: MKAnnotationView {
var imageView = UIImageView()
init(annotation: MKAnnotation?, reuseIdentifier: String?, size: CGSize) {
super.init(annotation: annotation, reuseIdentifier: reuseIdentifier)
self.frame = CGRectMake(0, 0, size.width, size.height)
self.commonInit()
}
override init(frame: CGRect) {
super.init(frame: frame)
}
required init?(coder: NSCoder) {
super.init(coder: coder)
}
func commonInit() {
self.imageView.frame = CGRectMake(0, 0, self.frame.width, self.frame.height)
self.imageView.layer.masksToBounds = true
self.imageView.layer.cornerRadius = self.imageView.frame.height/2
self.imageView.layer.borderWidth = 5.0
self.imageView.layer.borderColor = UIColor.whiteColor().CGColor
self.imageView.userInteractionEnabled = false
self.addSubview(imageView)
self.sendSubviewToBack(self.imageView)
}
}
then I set the annotationView
to be draggable
in the viewForAnnotation
然后我将
annotationView
viewForAnnotation
设置为draggable
在viewForAnnotation
draggable
func mapView(mapView: MKMapView, viewForAnnotation annotation: MKAnnotation) -> MKAnnotationView? {
var annotationView = mapView.dequeueReusableAnnotationViewWithIdentifier("pin") as? AMKAnnotationView
if annotationView == nil {
annotationView = AMKAnnotationView(annotation: annotation, reuseIdentifier: "pin", size: CGSizeMake(65, 65))
annotationView?.draggable = true
annotationView?.canShowCallout = true
let index = ... // i get the index
let location = ... // i get the current location
annotationView?.imageView.image = UIImage(named: "No Photo")
}
return annotationView
}
to make the annotationView
to be draggable
we should implement the didChangeDragState
delegate method 为了使
annotationView
可draggable
我们应该实现didChangeDragState
委托方法
func mapView(mapView: MKMapView, annotationView view: MKAnnotationView, didChangeDragState newState: MKAnnotationViewDragState, fromOldState oldState: MKAnnotationViewDragState) {
switch newState {
case .Starting:
view.dragState = .Dragging
case .Ending, .Canceling:
view.dragState = .None
// then i save the changes to CoreData
}
default: break
}
}
if i try to drag the annotation on the map it doesn't work 如果我尝试在地图上拖动注释,则无法正常工作
* The solution that i don't like * *我不喜欢的解决方案*
The way i got it work as of the title of this question says is to use MKPointAnnotation
and i mean by that is each time i add an annotation to the map i convert to MKPointAnnotation
which made me make another subclass of MKPointAnnotation
so that i can keep track of the location 就这个问题的标题而言,我得到它的方式是使用
MKPointAnnotation
,我的意思是,每次我向地图添加注释时,我将其转换为MKPointAnnotation
,这使我成为MKPointAnnotation
另一个子类,以便我可以保持位置追踪
class AMKPointAnnotation : MKPointAnnotation {
var location : Location!
init(location:Location) {
super.init()
self.location = location
self.title = location.title
self.subtitle = location.subtitle
self.coordinate = location.coordinate
}
}
and then for adding it to the MapView
然后将其添加到
MapView
for location in self.locations {
let pointAnnotation = AMKPointAnnotation(location: location)
self.MapView.addAnnotation(pointAnnotation)
}
any one tried it before ? 有人尝试过吗? What am I doing wrong?
我究竟做错了什么?
The coordinate
property changes with dragging and it must be read/write and since it was a computed property with no setter the MapKit prevented the dragging for that coordinate
属性随拖动而变化,并且它必须是可读写的,并且由于它是一个没有设置器的计算属性,因此MapKit阻止了拖动
* here is the solution * *这是解决方案*
class Location: NSManagedObject , MKAnnotation {
var coordinate : CLLocationCoordinate2D {
set {
self.latitude = newValue.latitude
self.longitude = newValue.longitude
}
get {
return CLLocationCoordinate2D(latitude: Double(self.latitude), longitude: Double(self.longitude))
}
}
var title: String? {
return self.name
}
var subtitle: String? {
return self.category
}
}
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