如何在 CoreData 中保存位置

Posted 2023-03-08

【中文标题】如何在 CoreData 中保存位置

【英文标题】：How to save Location in CoreData

【发布时间】：2017-09-18 03:44:37

【问题描述】：

当长按手势被识别时，我正在尝试在 ios CoreData 中保存一个标记的位置。每当我调用手势时，应用程序总是崩溃。我还将这两个的 coreData 类型设置为 Double。由于我对iOS开发还不是很熟悉，如何以最简单的方式将坐标安全地存储在coreData中。

    @IBAction func saveLocation(_ sender: Any) 
    guard let longPress = sender as? UILongPressGestureRecognizer else
     return 
    if longPress.state == .ended  
        let touchLocation = longPress.location(in: mapView)
        let coordinate = mapView.convert(touchLocation, toCoordinateFrom: mapView)

        let appDelegate = UIApplication.shared.delegate as! AppDelegate
        let context = appDelegate.persistentContainer.viewContext
        let newLocation = NSEntityDescription.insertNewObject(forEntityName: "GeoData", into: context)
        newLocation.setValue(coordinate.latitude as Double, forKey: "myLatitude")
        newLocation.setValue(coordinate.longitude as Double, forKey: "myLongitude")
        do
        
           try context.save()
        
        catch
        
        //ERROR
        
    

【问题讨论】：

什么是崩溃日志？

对不起，我想这可能只是我的愚蠢。我一定是刚刚输入了一个我没有注意到的断点。看来它保存正确。

【参考方案1】：

我创建了一个长按手势并将位置存储到这样的核心数据中--

创建一个长按手势并在核心数据中保存位置。

let longGesture = UILongPressGestureRecognizer(target: self, action: 
 #selector(longTap(_:)))
 mapView.addGestureRecognizer(longGesture)

func longTap(_ sender: UIGestureRecognizer)
    print("Long tap")
    if sender.state == .ended 
        print("UIGestureRecognizerStateEnded")
        //Do Whatever You want on End of Gesture
        let touchLocation = sender.location(in: mapView)
        let coordinate = mapView.convert(touchLocation, 
toCoordinateFrom: mapView)
        let appDelegate = UIApplication.shared.delegate as! AppDelegate
        let context = appDelegate.persistentContainer.viewContext
        let newLocation = 
NSEntityDescription.insertNewObject(forEntityName: "GeoData", into: 
context)
        newLocation.setValue(coordinate.latitude as Double, forKey: 
"myLatitude")
        newLocation.setValue(coordinate.longitude as Double, forKey: 
"myLongitude")
        do
        
            try context.save()
        
        catch
        
            //ERROR
            print(error)
        
    
    else if sender.state == .began 
        print("UIGestureRecognizerStateBegan.")
        //Do Whatever You want on Began of Gesture