我用Google搜索了如何查找国家/地区的列表并尝试实施到PickerView,但是我在这一点上陷入困境,我尝试做country.count它给了我一个错误说：
cannot convert return expression of type ‘int’ to return type ‘string’
any suggestions?
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.
}
}
您需要在方法numberOfRowsInComponent中返回数组计数,并且在titleForRow中需要返回数组对象,显示它将在picker中显示.
func pickerView(_ pickerView: UIPickerView,numberOfRowsInComponent component: Int) -> Int {
return countries.count
}
func pickerView(_ pickerView: UIPickerView,forComponent component: Int) -> String? {
return countries[row]
}
