Actually using UIDatePickerModeCountDownTimer as a timer

问题

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.

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;

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

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?

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

回答1:

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;

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

来源：https://stackoverflow.com/questions/3723448/actually-using-uidatepickermodecountdowntimer-as-a-timer