实际上使用UIDatePickerModeCountDownDownTimer作为计时器 [英] Actually using UIDatePickerModeCountDownTimer as a timer

问题描述

我只是想做一个计时器.我想使用UIDatePicker的UIDatePickerModeCountDownTimer模式，以便当用户在选择器中简单地选择说15分钟时，它们将被传递回屏幕，该屏幕在标签中显示15分钟的值，然后他们可以倒数.

I am just trying to make a timer. I would like to use UIDatePickerModeCountDownTimer mode of the UIDatePicker, so that when the user simply selects say 15 mins in the picker, they are passed back to a screen that shows the value of 15 mins in a label that they can then count down from.

当我尝试从DatePicker获取值时，我意识到选择器会传回一个NSTimeInterval，以秒为单位获取当前时间:

As I have tried to get the value from the DatePicker, I realized that the picker passes back an NSTimeInterval that gets the current time in seconds:

UIDatePicker *pickerView = [[UIDatePicker alloc] init];
NSTimeInterval new = (NSTimeInterval)pickerView.countDownDuration;

所以我只想知道用户选择的值，而不是当前时间(以秒为单位).

So all I want is to know the value that the user selected, not the current time in seconds.

我正在尝试从UIActionSheet中显示的DatePicker传回此数据...对正在发生的事情或我做错了什么的任何想法?

I am trying to pass this data back from a DatePicker that is being presented in a UIActionSheet...any thoughts about what is going on or what I am doing wrong?

我只想要一个计时器！!!!!!!

I just want a timer!!!!!!!

推荐答案

您的代码缺少一行，您必须为UIDatePicker设置模式.完整的代码应为:

Your code lacks a line, you have to set the mode for your UIDatePicker. The full code should be:

UIDatePicker *pickerView = [[UIDatePicker alloc] init];
pickerView.datePickerMode = UIDatePickerModeCountDownTimer;

// please DON'T use new because it is objc syntax
NSTimeInterval timeInterval = (NSTimeInterval)pickerView.countDownDuration;

，然后如果您不知道如何将NSTimeInterval(秒)转换为分钟，则可以使用

and then if you don't know how to convert your NSTimeInterval (seconds) to minutes, you can use this question

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