如何在 iOS 中的 UIDatePicker 中禁用上一次

Question

我想从 datePicker 禁用以前的时间，即在当前时间之前，就像在日期选择器中一样，我们可以使用最小日期来做到这一点。我们怎么能用时间选择器做同样的事情。

这是代码。`

  timePicker = [[UIDatePicker alloc] init];
  [self.view addSubview:timePicker];
  float tempHeight = timePicker.frame.size.height;
  timePicker.frame = CGRectMake(0,200 ,self.view.frame.size.width , tempHeight);
  timePicker.hidden = YES;
  timePickerFormatter= [[NSDateFormatter alloc]init ];
  [timePickerFormatter setDateFormat:@"HH:mm"]; 

  **timePicker.datePickerMode = UIDatePickerModeCountDownTimer;**
  timePicker.minuteInterval=15;

`

提前致谢 如果有任何方法可以执行此操作，请建议我。

Answer 1

在默认的 UIDatePicker 可以设置最小日期，并且 date 属性具有日期和时间值，您可以在那里自行设置

   [datePicker setMinimumDate:[NSDate date]];

这里

[NSDate date]

给出当前日期

Answer 2

所以你想从当前时间禁用以前的时间。

timePicker.date = [NSDate date];

这将时间设置为当前时间，但我认为您不能禁用上一次。

Answer 3

通过这种方法，如果用户选择了过去的时间，您可以向用户提供警报。 条件是您已经将最小日期作为当前日期进行了检查。

func handleTimePicker(sender: UIDatePicker) {

    let timeFormatterHour = NSDateFormatter()
    let timeFormatterMinutes = NSDateFormatter()
    timeFormatterHour.dateFormat = "hh"
    timeFormatterMinutes.dateFormat = "mm"
    let InputTimeHourString = timeFormatterHour.stringFromDate(sender.date)
    let InputTimeMinutesString = timeFormatterMinutes.stringFromDate(sender.date)
    let InputTimeHourInt = Int(InputTimeHourString)!
    let InputTimeMinutesInt = Int(InputTimeMinutesString)!
    let calculatedInputMinutes = (InputTimeHourInt * 60) + InputTimeMinutesInt

    let TodayTime = NSDate()
    let TodayTimetimeFormatterHour = NSDateFormatter()
    let TodayTimetimeFormatterMinutes = NSDateFormatter()
    TodayTimetimeFormatterHour.dateFormat = "hh"
    TodayTimetimeFormatterMinutes.dateFormat = "mm"
    let TodayTimeInputTimeHourString = TodayTimetimeFormatterHour.stringFromDate(TodayTime)
    let TodayTimeInputTimeMinutesString = TodayTimetimeFormatterMinutes.stringFromDate(TodayTime)
    let TodayTimeInputTimeHourInt = Int(TodayTimeInputTimeHourString)!
    let TodayTimeInputTimeMinutesInt = Int(TodayTimeInputTimeMinutesString)!
    let TodayTimecalculatedInputMinutes = (TodayTimeInputTimeHourInt * 60) + TodayTimeInputTimeMinutesInt

    if TodayTimecalculatedInputMinutes - calculatedInputMinutes < 0
    {
        let shownDateFormatter = NSDateFormatter()
        shownDateFormatter.dateFormat = "hh:mm a"
        self.txtTimeEvent.text = shownDateFormatter.stringFromDate(sender.date)
    }
    else
    {
        let alertController = UIAlertController(title: "Time Selection Problem", message:
            "You cannot select the Past time", preferredStyle: UIAlertControllerStyle.Alert)
        alertController.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.Default,handler: nil))
        self.presentViewController(alertController, animated: true, completion: nil)
        let shownTime = NSDate()
        let shownTimeFormatter = NSDateFormatter()
        shownTimeFormatter.dateFormat = "hh:mm a"
         self.txtTimeEvent.text = shownTimeFormatter.stringFromDate(shownTime)

    }
}

Answer 4

Swift ：在你的 Picker Function.its Only Allow future Time 中添加这一行。

My_Pickername.minimumDate = NSDate()

Answer 5

您两年前发布了您的问题，但这可能会对遇到此问题的任何人有所帮助，我今天遇到了同样的问题，以下是解决方案：
它并没有真正禁用以前的日期，但是如果用户选择了以前的日期，则上述函数将显示警报并将 UIDatePicker 重置为当前日期：

斯威夫特 4：

@IBAction func dateChanged(_ sender: Any) {
    let dtp = sender as! UIDatePicker
    if Date() <= dtp.date
        {
        print ("correct date")
    }
    else
    {
        dtp.date = Date()
        let alert = UIAlertController(title: "Error", message: "You have to choose a correct date", preferredStyle: .alert)
        let action = UIAlertAction(title: "OK", style: .default, handler: nil)
        alert.addAction(action)
        self.present(alert, animated: true, completion: nil)
    }
}