如何使用 JSON 文件中的信息填充数组并计算距离？

Question

我这里有一个 JSON 文件：

     {
      "People": [{
       "A1": "New York",
       "B1": "ShoppingMall1",
       "C1": "43.0757",
       "D1": "23.6172"
       },
       {
       "A1": "London",
       "B1": "ShoppingMall2",
       "C1": "44.0757",
       "D1": "24.6172"
       }, {
       "A1": "Paris",
       "B1": "ShoppingMall3",
       "C1": "45.0757",
       "D1": "25.6172"
       }, {
       "A1": "Bern",
       "B1": "ShoppingMall4",
       "C1": "41.0757",
       "D1": "21.6172"
       }, {
       "A1": "Sofia",
       "B1": "ShoppingMall5",
       "C1": "46.0757",
       "D1": "26.6172"

       }
       ]
       }

我必须从这个 JSON 文件中获取购物中心的名称和坐标，并将它们填充到一个数组中。我想在表格视图单元格中使用这个数组。主要思想是计算用户当前位置周围最近的购物中心。这里我计算用户的当前位置。

@IBAction func LocateMe(sender: AnyObject) {
manager.delegate = self
manager.desiredAccuracy = kCLLocationAccuracyBest
manager.requestWhenInUseAuthorization()
manager.startUpdatingLocation()




   }
   func  locationManager(manager: CLLocationManager, didUpdateLocations      locations: [CLLocation]) {
let userlocation: CLLocation = locations[0] as CLLocation
manager.stopUpdatingLocation()
let location = CLLocationCoordinate2D(latitude: userlocation.coordinate.latitude, longitude: userlocation.coordinate.longitude)
let span = MKCoordinateSpanMake(0.5, 0.5)
let region = MKCoordinateRegion(center: location, span: span)

   }
   let distanceMeters = userlocation.distanceFromLocation(CLLocation(latitude: ??,longitude: ??))
let distanceKilometers = distanceMeters / 1000.00
let roundedDistanceKilometers = String(Double(round(100 * distanceKilometers) / 100)) + " km"

但我不知道如何获取所有购物中心的坐标并进行比较。我也不知道如何将它们填充到我需要用于表格视图单元格的数组中。我是 swift 的新手，我如果有人可以帮助我，我会很高兴。

Answer 1

我一直在研究你的问题，这是我的结果，

首先我建议你使用一个JSON framework，比如SwiftyJSON，但我不使用任何一个，因为我不知道你是否愿意，所以

首先我们需要使用这段代码加载我们的 json

let pathForPlist = NSBundle.mainBundle().pathForResource("JSON", ofType: "json")!
let JSONData = NSData(contentsOfFile: pathForPlist)

在我们需要解析这些数据并转换为 JSONObject 之后

let JSONObject = try NSJSONSerialization.JSONObjectWithData(JSONData!, options: NSJSONReadingOptions.MutableContainers) as! [String:AnyObject]

并使用 Dictionary 中的初始化程序正确转换为 Objects，注意我们使用 NSJSONReadingOptions.MutableContainers，因为我们的 json 是一个字典数组

这是完整的代码，请注意，我为您的数据类型定义了一个名为 ObjectShop 的类，以帮助稍后进行计算

import UIKit
import MapKit

class ObjectShop
{
    var A1 = ""
    var B1 = ""
    var C1 = ""
    var D1 = ""

    init?(dict:[String:AnyObject])
    {
        A1 = dict["A1"] as! String
        B1 = dict["B1"] as! String
        C1 = dict["C1"] as! String
        D1 = dict["D1"] as! String
    }

    func getCoordenate2D() -> CLLocationCoordinate2D
    {
        return CLLocationCoordinate2D(latitude: Double(self.C1)!, longitude: Double(self.D1)!)
    }
}

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        let pathForPlist = NSBundle.mainBundle().pathForResource("JSON", ofType: "json")!
        let JSONData = NSData(contentsOfFile: pathForPlist)
        do
        {
            var objects = [ObjectShop]()
            let JSONObject = try NSJSONSerialization.JSONObjectWithData(JSONData!, options: NSJSONReadingOptions.MutableContainers) as! [String:AnyObject]
            print(JSONObject)
            for dic in JSONObject["People"] as! [[String:AnyObject]] {
                print(dic)
                let objc = ObjectShop(dict: dic)
                objects.append(objc!)
            }

            for object in objects {
                print(object.getCoordenate2D())
            }
        }
        catch _
        {

        }

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


}

希望对你有帮助，如果有任何问题，请告诉我