Question

我正在尝试使用UserDefaults存储自定义类的数组。自定义类用于使用字符串和CLLocationCoordinate2D的混合注释。

当我在地图视图中执行长按手势时，我正在呼叫ArchiveUtil.savePins(pins: pins)。

然而，我收到错误

- [NSKeyedArchiver encodeValueOfObjCType：at：]：此归档程序无法对结构进行编码＆＃39;

任何想法我做错了什么？

谢谢，代码如下：

class PinLocation: NSObject, NSCoding, MKAnnotation {

    var title: String?
    var subtitle: String?
    var coordinate: CLLocationCoordinate2D

    init(name:String, description: String, lat:CLLocationDegrees,long:CLLocationDegrees){
        title = name
        subtitle = description
        coordinate = CLLocationCoordinate2DMake(lat, long)
    }

    required init?(coder aDecoder: NSCoder) {
        title = aDecoder.decodeObject(forKey: "title") as? String
        subtitle = aDecoder.decodeObject(forKey: "subtitle") as? String
        coordinate = aDecoder.decodeObject(forKey: "coordinate") as! CLLocationCoordinate2D
    }

    func encode(with aCoder: NSCoder) {
        aCoder.encode(title, forKey: "title")
        aCoder.encode(subtitle, forKey: "subtitle")
        aCoder.encode(coordinate, forKey: "coordinate")
    }

}

class ArchiveUtil {

    private static let PinKey = "PinKey"

    private static func archivePins(pin: [PinLocation]) -> NSData{

        return NSKeyedArchiver.archivedData(withRootObject: pin as NSArray) as NSData
    }


    static func loadPins() -> [PinLocation]? {

        if let unarchivedObject = UserDefaults.standard.object(forKey: PinKey) as? Data{

            return NSKeyedUnarchiver.unarchiveObject(with: unarchivedObject as Data) as? [PinLocation]
        }

        return nil

    }

    static func savePins(pins: [PinLocation]?){

        let archivedObject = archivePins(pin: pins!)
        UserDefaults.standard.set(archivedObject, forKey: PinKey)
        UserDefaults.standard.synchronize()
    }

}

Answer 1

错误很明显：CLLocationCoordinate2D是struct而此归档程序无法对结构进行编码。

一个简单的解决方法是分别对latitude和longitude进行解码和解码。

顺便说一句，由于两个String属性都使用非可选值初始化，因此将它们声明为非可选属性。如果它们不被改变，则将它们声明为常量（let）

var title: String
var subtitle: String

...

required init?(coder aDecoder: NSCoder) {
    title = aDecoder.decodeObject(forKey: "title") as! String
    subtitle = aDecoder.decodeObject(forKey: "subtitle") as! String
    let latitude = aDecoder.decodeDouble(forKey: "latitude")
    let longitude = aDecoder.decodeDouble(forKey: "longitude")
    coordinate = CLLocationCoordinate2D(latitude: latitude, longitude: longitude)
}

func encode(with aCoder: NSCoder) {
    aCoder.encode(title, forKey: "title")
    aCoder.encode(subtitle, forKey: "subtitle")
    aCoder.encode(coordinate.latitude, forKey: "latitude")
    aCoder.encode(coordinate.longitude, forKey: "longitude")
}

自定义类存储 - 无法编码结构

1 个答案: