名单的国家成为uipickerview SWIFT 3

Question

我GOOGLE如何找到国家名单，并试图落实到PickerView，但我被困在这一点上，我尝试做countries.count它给了我一个错误说：

无法将类型'int'的返回表达式转换为返回类型'string' 有什么建议吗？

import UIKit 

class ViewController: UIViewController, UIPickerViewDataSource, UIPickerViewDelegate{ 
    @IBOutlet weak var pickerValue: UIPickerView! 

    let countries = NSLocale.isoCountryCodes.map { (code:String) -> String in 
     let id = NSLocale.localeIdentifier(fromComponents: [NSLocale.Key.countryCode.rawValue: code]) 
     return NSLocale(localeIdentifier: "en_US").displayName(forKey: NSLocale.Key.identifier, value: id) ?? "Country not found for code: \(code)" 
    } 

    func numberOfComponents(in pickerView: UIPickerView) -> Int { 
     return 1 
    } 

    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? { 
     return countries.count 
    } 

    override func viewDidLoad() { 
     super.viewDidLoad() 
     // Do any additional setup after loading the view, typically from a nib. 
    } 

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

Answer 1

您需要返回数组中的方法numberOfRowsInComponent和计数titleForRow您需要返回数组对象，表明其将在选择器显示。

func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int { 
    return countries.count 
} 

func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? { 
    return countries[row] 
}