Question

import MapKit
import UIKit

class Point: NSObject, MKAnnotation {
    var id: String?
    var title: String?
    var coordinate: CLLocationCoordinate2D
    var subtitle: String?



    init(id: String, dictionary: Dictionary<String, AnyObject>){


        self.id = id

        if let title = dictionary["title"] as? String {
            self.title = title
        }

        if let subtitle = dictionary["subtitle"] as? String {
            self.subtitle = subtitle
        }

        if let coords = dictionary["coordinates"] as? [String:[String:Double]] {
            var latitude = coords.values.first!["latitude"]!
            var longitude = coords.values.first!["longitude"]!
            var location = CLLocationCoordinate2D(latitude: latitude, longitude: longitude)
            self.coordinate = location
        }

    }

错误：属性self.coordinate未在隐式生成的super.init调用中初始化。

任何想法如何解决这个问题？

感谢您的一些建议。

Answer 1

您应该在

的其他情况下指定默认值

if let coords = dictionary["coordinates"] as? [String:[String:Double]] {
...
} else {
self.coordinate = <assign a default location>
}

或者

如果没有坐标，则不应创建对象。所以让你的init可选。

 init?(id: String, dictionary: Dictionary<String, AnyObject>){

      if let coords = dictionary["coordinates"] as? [String:[String:Double]] {
           self.id = id

           if let title = dictionary["title"] as? String {
                self.title = title
           }

           if let subtitle = dictionary["subtitle"] as? String {
                self.subtitle = subtitle
           }
           var latitude = coords.values.first!["latitude"]!
           var longitude = coords.values.first!["longitude"]!
           var location = CLLocationCoordinate2D(latitude: latitude, longitude: longitude)
           self.coordinate = location
      } else {
           return nil
      }
 }

自定义MKAnnotation字典输入（CLLocationCoordinate2d）

1 个答案: