Dateformatter日期字符串返回nil

Question

當我使用DatePicker設置日期時

它說沒有

盡管我檢查了日期字符串格式是否正確

並且dateFormat設置為我想要的格式。

這是代碼

class DatePickerViewController: UIViewController {

var originDate: String!{ 
        didSet{
            //print("\(originDate)") is like "2019/07/12"
            selectedDate = dateFormatter.date(from: originDate)
           //print("\(selectedDate)") is nil
            datePicker.setDate(selectedDate, animated: true)
        }
 }

var selectedDate: Date!
var dateString: String = "yyyy/MM/dd"
var dateFormatter: DateFormatter = DateFormatter()

override func viewDidLoad() {

        dateFormatter.dateFormat = dateString

}

ShowPickerViewController調用DatePickerViewController

class ShowPickerViewController:UIViewcontroller {

   @IBAction func showDatePicker(_ sender: Any) {

   let vc = DatePickerViewController()

   vc.originDate = sender.text // "2019/07/12"

   present(vc, animated: true)

   }

}

Answer 1

用閉包初始化日期格式

let dateFormatter: DateFormatter = {
   let formatter = DateFormatter()
   formatter.dateFormat = "yyyy/MM/dd"
   return formatter
}()

並刪除viewDidLoad的行