平移或缩放到新区域时,很难显示注释。如果平移到新的地图区域,则不会显示任何内容,但是如果我在其中进行小平移,则会显示注释。我希望注释显示出来而用户无需平移多次。
我发现的类似问题似乎已经通过在主线程上加载批注解决了,但是到目前为止,我可能在主线程上运行了所有内容,这是不可取的。
我已经包括了我的regionDidChange和regionWillChange函数,在其中我对mapView和Annotate函数进行了注释。
func mapView(_ mapView: MKMapView, regionWillChangeAnimated animated: Bool) {
zoomLevelBeforeChange = ((mapView.getZoomLevel() * 100).rounded() / 100)
}
func mapView(_ mapView: MKMapView, regionDidChangeAnimated animated: Bool) {
var apiScale: String
print("Zoom: \(mapView.getZoomLevel())")
if mapView.getZoomLevel() < 5 {
mapView.setCenter(coordinate: mapView.centerCoordinate, zoomLevel: 5, animated: true)
apiScale = "6"
} else if mapView.getZoomLevel() >= 5.0 && mapView.getZoomLevel() < 6.0 {
apiScale = "6"
} else if mapView.getZoomLevel() >= 6.0 && mapView.getZoomLevel() < 7.5 {
apiScale = "7"
} else if mapView.getZoomLevel() >= 7.5 && mapView.getZoomLevel() < 8.5 {
apiScale = "9"
} else if mapView.getZoomLevel() >= 8.5 && mapView.getZoomLevel() <= 9.5 {
apiScale = "11"
} else if mapView.getZoomLevel() >= 9.5 && mapView.getZoomLevel() <= 10.0 {
apiScale = "13"
} else if mapView.getZoomLevel() > 10 {
mapView.setCenter(coordinate: mapView.centerCoordinate, zoomLevel: 10, animated: true)
apiScale = "13"
} else {
apiScale = "0"
}
print(apiScale)
if ((mapView.getZoomLevel() * 100).rounded() / 100) == zoomLevelBeforeChange {
print("don't remove annotations")
} else {
let allAnnotations = self.mapView.annotations
self.mapView.removeAnnotations(allAnnotations)
}
let latitudeDelta = mapView.region.span.latitudeDelta
let longitudeDelta = mapView.region.span.longitudeDelta
let centerCoordLat = mapView.centerCoordinate.latitude
let centerCoordLong = mapView.centerCoordinate.longitude
lowerLeftLong = (centerCoordLong - (longitudeDelta / 2))
lowerLeftLat = (centerCoordLat - (latitudeDelta / 2))
upperRightLong = (centerCoordLong + (longitudeDelta / 2))
upperRightLat = (centerCoordLat + (latitudeDelta / 2))
mapUrl = "http://api.openweathermap.org/data/2.5/box/city?bbox=\(lowerLeftLong!),\(lowerLeftLat!),\(upperRightLong!),\(upperRightLat!),\(apiScale)&appid=(appId)"
downloadMapWeatherApi {
annotate()
self.mapAnnotations = []
}
}
func downloadMapWeatherApi(completed: DownloadComplete) {
Alamofire.request(self.mapUrl).responseJSON { response in
let result = response.result
if let dict = result.value as? Dictionary<String, AnyObject> {
if let list = dict["list"] as? [Dictionary<String, AnyObject>] {
for obj in list {
let annotation = MapAnnotation(locationDict: obj)
self.mapAnnotations.append(annotation)
}
}
}
}
completed()
}
func annotate() {
for location in self.mapAnnotations {
let annotation = CustomAnnotation()
annotation.title = location.cityName
annotation.subtitle = "\(Int(location.temperature))°"
annotation.attribute = location.weatherType
annotation.coordinate = CLLocationCoordinate2D(latitude: location.latitude, longitude: location.longitude)
mapView.addAnnotation(annotation)
}
}
谢谢!
最佳答案
一个非常简单的修复程序,但是花了我很长时间才弄清楚。我不知道其背后的原因,但看来我的注释数组始终来自上一个mapView rect。我将注释功能移到了天气数据api调用中,并对其进行了纠正。
func downloadMapWeatherApi(completed: DownloadComplete) {
Alamofire.request(self.mapUrl).responseJSON { response in
let result = response.result
if let dict = result.value as? Dictionary<String, AnyObject> {
if let list = dict["list"] as? [Dictionary<String, AnyObject>] {
for obj in list {
let annotation = MapAnnotation(locationDict: obj)
self.mapAnnotations.append(annotation)
}
self.annotate()
}
}
}
completed()
}
希望这可以帮助遇到类似问题的人。