问解析本地JSON数据

EN

[
    {
        "city": "Tokyo", 
        "admin": "T\u014dky\u014d", 
        "country": "Japan", 
        "population_proper": "8336599", 
        "iso2": "JP", 
        "capital": "primary", 
        "lat": "35.685", 
        "lng": "139.751389", 
        "population": "35676000"
    }, 
    {
        "city": "\u014csaka", 
        "admin": "\u014csaka", 
        "country": "Japan", 
        "population_proper": "2592413", 
        "iso2": "JP", 
        "capital": "admin", 
        "lat": "34.683333", 
        "lng": "135.516667", 
        "population": "11294000"
    }
]

    struct JapCity: Codable {
        var city: String
        var admin: String
        var country: String
        var population: String
        var lat: String
        var lng: String
    }
    
    var japcityinfo = [JapCity]()
    
    
    @IBOutlet weak var cityPicker: UIPickerView!

    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        
        cityPicker.delegate = self
        cityPicker.dataSource = self
        
        jasonCall()
        
        cityPicker.reloadAllComponents()
        
    }

    func numberOfComponents(in pickerView: UIPickerView) -> Int {
        return 1
    }
    
    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        return japcityinfo.count
    }
    
    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
        print("here")
        return japcityinfo[row].city
    }
    
    
    func jasonCall() {
        let decoder = JSONDecoder()

        do {
            //let jsonData = Data(jsonString.utf8)
            let path = Bundle.main.path(forResource: "jp", ofType: "json")
            guard path != nil else {
                print("Error: Can't find JSON file")
                return
            }
            let url = URL(fileURLWithPath: path!)
            let data = try Data(contentsOf: url)
            
            let japancity = try decoder.decode([JapCity].self, from: data)
            
            print(japancity)
            print(japancity.count)
            let citydataNum = japancity.count
            print(citydataNum)
            
        } catch {
            print(error.localizedDescription)
        }
        
    }

}