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我有一個應用程序,可以從Core Data模型中獲取數據,然後我希望在地圖上顯示這些數據。當我向地圖視圖添加註釋時,出現以下錯誤:無法將類型'Swift._ContiguousArrayStorage <>'()的值轉換爲'MKAnnotation'()。這同樣的邏輯適用於Swift 2,但顯然不適用於Swift 3.我在哪裏以及如何將符號添加到地圖視圖。的代碼是:向地圖視圖添加註釋時出錯
override func viewDidAppear(_ animated: Bool) {
var rainFallGauges = [RainFallGauge]()
let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: "RainFallGauge")
do {
rainFallGauges = try coreDataStack.context.fetch(fetchRequest) as! [RainFallGauge]
obsCount = rainFallGauges.count
} catch let error as NSError {
print("Could not fetch \(error), \(error.userInfo)")
}
if obsCount == 0 {
let alert = UIAlertController(title: "Sorry", message: "No gauges found", preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.default, handler: nil))
self.present(alert, animated: true, completion: nil)
} else {
for rainFallGauge in rainFallGauges {
resultsGauge = rainFallGauge.value(forKey: "gaugeName") as? String
resultsLatitude = rainFallGauge.value(forKey: "gaugeLatitude") as? String
resultsLongitude = rainFallGauge.value(forKey: "gaugeLongitude") as? String
print(resultsGauge)
if (resultsLatitude != nil && resultsLongitude != nil) && (resultsLatitude?.isEmpty == false && resultsLongitude?.isEmpty == false) {
let latNSString = NSString(string: resultsLatitude!)
setLatitude = latNSString.doubleValue
print(setLatitude)
let longNSString = NSString(string: resultsLongitude!)
setLongitude = longNSString.doubleValue
print(setLongitude)
self.gauges.append(Gauges(gaugeTitle: resultsGauge, latitude: setLatitude, longitude: setLongitude))
print(gauges.count)
} else if gauges.count == 0 {
let alert = UIAlertController(title: "Sorry", message: "No gauges", preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.default, handler: nil))
self.present(alert, animated: true, completion: nil)
}
}
}
self.gaugeMap.delegate = self
self.gaugeMap.addAnnotation(self.gauges as! MKAnnotation)
gaugeMap.mapType = .hybrid
let rectToDisplay = self.gauges.reduce(MKMapRectNull) {
(mapRect: MKMapRect, gauge: Gauges) -> MKMapRect in
let placePointRect = MKMapRect(origin: gauge.location.mapPoint, size: MKMapSize(width: 0, height: 0))
return MKMapRectUnion(mapRect, placePointRect)
}
我有數組「儀表」如上所聲明的:
var gauges = [Gauges]()
和已創建的類儀表來保存註釋相關的信息。
任何建議,將引導我到addAnnotation語句的正確語法,它應該去的地方,將不勝感激。
此行是沒有意義的:'self.gaugeMap.addAnnotation(
我通過簡化和要解決我的問題self.gauges as!MKAnnotation)'如果'self.gauges'是一個'[Gauges]'它怎麼可能是一個MKAnnotation?不要告訴我在Swift 2中以某種方式工作;無論你在說什麼語言,都是無稽之談。 – matt
是MKAnnotation的Gauges子類? –
感謝您提供寶貴的見解,我誤解了我舊應用中的這一行: – user1698875