对于应该是一段非常简单的代码,我有几个问题。目标是从数据库中读取项目并将它们固定在 map 上。如果项目已被标记为收藏夹,图钉应该是不同的颜色。
第一个问题是不是所有的项目都被渲染。在示例中,我将使用查询返回的 12 个结果,并且我已验证每个项目都创建了一个 MKAnnotation,并且每个注释都调用了 ViewFor。
除了不显示所有引脚外,还有另外两个问题。
滚动 map 时,第一个 Pin 图会随机丢失其标题。
其次最喜欢的(绿色)很少呈现绿色。 80% 的时间它以标准蓝色出现。我再次确认 MKMarkerAnnotationView 颜色设置正确。
鉴于所有这些问题,我不得不得出结论,我在做一些根本上非常错误的事情。这很奇怪,因为这看起来非常简单。
class FacilityMarker: NSObject, MKAnnotation {
// title and subtitle are from the MKAnnotation protocol
var coordinate: CLLocationCoordinate2D
var title: String?
var address: String
var phone: String
var providerNumber: String
var favorite: Bool
var subtitle: String? {
get {
return phone
}
}
View Controller
class MapViewController: UIViewController, CLLocationManagerDelegate, MKMapViewDelegate {
@IBOutlet weak var mapView: MKMapView!
override func viewDidLoad() {
super.viewDidLoad()
mapView.delegate = self
mapView.showAnnotations(mapView.annotations, animated: true)
// Create Annotations for all the facilities that are now visible on map
func mapView(_ mapView: MKMapView, regionDidChangeAnimated animated: Bool) {
let edgePoints = mapView.edgePoints()
let minLat = edgePoints.ne.latitude < edgePoints.sw.latitude ? edgePoints.ne.latitude : edgePoints.sw.latitude
let maxLat = edgePoints.ne.latitude > edgePoints.sw.latitude ? edgePoints.ne.latitude : edgePoints.sw.latitude
let minLong = edgePoints.ne.longitude < edgePoints.sw.longitude ? edgePoints.ne.longitude : edgePoints.sw.longitude
let maxLong = edgePoints.ne.longitude > edgePoints.sw.longitude ? edgePoints.ne.longitude : edgePoints.sw.longitude
let visibleCitiesReqeuest =
managedObjectModel.fetchRequestFromTemplate(withName: "FetchByCoordinates", substitutionVariables: ["minLat" : minLat, "minLong" : minLong, "maxLat" : maxLat, "maxLong" : maxLong])
do {
let facilities = try CoreDataHelper.shared.persistentContainer.viewContext.fetch(visibleCitiesReqeuest!) as! [FacilityMO]
for facility in facilities {
let facilityMarker = FacilityMarker(name: facility.facilityName!, address: facility.addressLine1!, location: facility.location!, phone: facility.phoneNumber!, providerNumber: facility.providerNumber!, favorite: facility.favorite)
mapView.addAnnotation(facilityMarker)
}
} catch {
let alertController = UIAlertController(title: "No Facilities", message: "There are no Facilities within the visible map area", preferredStyle: .alert)
alertController.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.cancel, handler: nil))
self.present(alertController, animated: true, completion: nil)
}
}
// Put the pins in the map
func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
guard let annotation = annotation as? FacilityMarker else { return nil}
let identifier = "facility"
var view: MKMarkerAnnotationView
if let dequeuedView = mapView.dequeueReusableAnnotationView(withIdentifier: identifier) as?
MKMarkerAnnotationView {
dequeuedView.annotation = annotation
view = dequeuedView
} else {
print("CREATING NEW View for: \(annotation.title!)")
view = MKMarkerAnnotationView(annotation: annotation, reuseIdentifier: identifier)
}
// Set the Colors
if (annotation.favorite) {
view.markerTintColor = .green
view.tintColor = .green
} else {
view.markerTintColor = .blue
view.tintColor = .blue
}
return view
}
这是查询返回的实际数据。只有突出显示的项目才会被渲染。 这在所有测试中都是 100% 一致的。
-
CREATING NEW View for: SEMINOLE DIALYSIS CENTER
- 为以下项目创建新 View :塞米诺尔湖透析
-
CREATING NEW View for: RAI CARE CENTERS - LARGO
-
CREATING NEW View for: BAY BREEZE DIALYSIS CLINIC INC
- 为 CLEARWATER, LLC 的 RENVIVA 透析中心创建新 View
-
CREATING NEW View for: FKC - BELLEAIR DIALYSIS CENTER
-
CREATING NEW View for: RAI CARE CENTERS - CLEARWATER
- 为 FMC - BELLEAIR HOME THERAPIES 创造新视野
-
CREATING NEW View for: CORVA GULF COAST DIALYSIS CENTER
- 为 GULF BREEZE 透析中心创建新 View
-
CREATING NEW View for: BMA - CLEARWATER
- 为 RAI-US 19 NORTH-CLEARWATER 创建新 View
以下是显示上述结果的截图
这是一个初始渲染。这次 BMA 引脚是蓝色的,它被设置为绿色。
这次滚动后 BMA 色调是正确的。没有什么时候是正确的模式。
更多的滚动只是为了增加更多的奇怪性,有时一个或多个注释不会呈现它们的标题属性
请求调试的输出:
- RAI CARE CENTERS - LARGO 是蓝色的
- BMA - CLEARWATER 是绿色的
- RENVIVA DIALYSIS CENTER OF CLEARWATER, LLC 是蓝色的
- RAI 护理中心 - CLEARWATER 是蓝色的
- FKC - BELLEAIR 透析中心是蓝色的
- FMC - BELLEAIR HOME THERAPIES 是蓝色的
- GULF BREEZE 透析中心是蓝色的
- BAY BREEZE DIALYSIS CLINIC INC 是蓝色的
- RAI-US 19 NORTH-CLEARWATER 是蓝色的
- CORVA GULF COAST DIALYSIS CENTER 是蓝色的
最佳答案
尝试以下调试代码。你能显示输出吗?
...
// Set the Colors
if (annotation.favorite) {
print(annotation.title, "is green")
view.markerTintColor = .green
view.tintColor = .green
} else {
print(annotation.title, "is blue")
view.markerTintColor = .blue
view.tintColor = .blue
}
...
关于ios - map 注释有很多问题,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/49532389/