How can I set the UIDatePickerModeCountDownTimer's maximum time?

Question

I want to ask that how can I set the iOS Count Down Timer's maximum time? (eg. 1 hour and 30 minutes at most)

Count Down Timer is get from UIDatePicker's mode:

Thanks!

EDIT:

Someone said I have to set the minimum/maximum date, and I just set them in the storyboard but I don't see any difference:

(the time of the setting is my local time +- 30 minutes)

EDIT:

From Apple:

The minimum and maximum dates are also ignored in the countdown-timer mode (UIDatePickerModeCountDownTimer).

So is their anyway to do this?

Answer 1

In your case for UIDatePickerModeCountDownTimer you can handle it programmatically

Add an event called when the value of your UIDatePicker has changed.

Objective-C

[self.datePicker addTarget:self action:@selector(datePickedValueChanged:)
     forControlEvents:UIControlEventValueChanged];

Swift

self.datePicker.addTarget(self, action: Selector("datePickedValueChanged:"), forControlEvents: UIControlEvents.ValueChanged)

Then if the value selected is out of allowed selection, you can set the DatePicker to maximum allowed valued (or whichever you want)

Objective-C

- (void)datePickedValueChanged:(id)sender{
    if (self.datePicker.countDownDuration > 5400.0f) { //5400 seconds = 1h30min
        [self.datePicker setCountDownDuration: 60.0f]; //Defaults to 1 minute
    }
}

Swift

func datePickedValueChanged (sender: UIDatePicker) {
    if (self.datePicker.countDownDuration > 5400) { //5400 seconds = 1h30min
        self.datePicker.countDownDuration = 60.0; //Defaults to 1 minute
    }
}

-- Previous answer :

I leave previous answer for others using a UIDatePicker in Date or DateAndTime mode, if that can help some people

You can set minimum and maximum date of your UIDatePicker.

Here user can't select a time before present time, and just go ahead 1 hour and 30 minutes.

Any attempt to select another time will make the UIDatePicker to automatically go back to an allowed time interval.

NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDate *currentDate = [NSDate date];

NSDateComponents *dateDelta = [[NSDateComponents alloc] init];
[dateDelta setDay:0];
[dateDelta setHour:1];
[dateDelta setMinute:30];
NSDate *maximumDate = [calendar dateByAddingComponents:dateDelta toDate:currentDate options:0];
[self.datePicker setMaximumDate:maximumDate];

[dateDelta setDay:0];
[dateDelta setHour:0];
[dateDelta setMinute:0];
NSDate *minimumDate = [calendar dateByAddingComponents:dateDelta toDate:currentDate options:0];

[self.datePicker setMinimumDate:minimumDate];

Answer 2

You can use NSTimer and set interval then update the NSDatePicker

1. declared a global variable int limiter = 0; and the NSDate holder for previous time;

2. add target to your NSDatePicker

---

[self.YourDatePicker addTarget:self action:@selector(dateChanged:)forControlEvents:UIControlEventValueChanged];

Set the interval to 60 == 1min

NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:60 target:self selector:@selector(updateTime) userInfo:nil repeats:YES];

---

- (void) dateChanged:(UIDatePicker *)sender
{
    // handle date changes

     NSDate *set = sender.date; // time setted 

    // compute the difference base from this to `[NSDate timeIntervalSinceDate:]`

    NSDate *now = [NSDate date];

    // logic `limit = now - set (greater then the current time)`
}


- (void)updateTime
{
    NSLog(@"fired");

    limiter--; // 

    if (limiter == 0)
    {
        // TIME IS UP
        [timer invalidate];
        return;
    }

    NSDate *now = self.fourthProfileBirthdate.date;

    NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];

    NSDateComponents *offsetComponents = [[NSDateComponents alloc] init];
    [offsetComponents setYear:-1]; // countdown subtracting  here from the current time

    // NSDate
    self.YourDatePicker.date = [gregorian dateByAddingComponents:offsetComponents toDate:now options:0];

}

Sorry i can't continue this in detail i need to go home..

But hope this helps you.. Cheers!

Answer 3

While Niko's solution works, it's downside is that the count of hours remains large. If you want to actually limit the hours that are displayed, I built a custom picker for just that purpose. It's a subclass of UIPickerView and it replicates the functionality of UIDatePicker in countDownTimer mode, while adding support to set maxTimeInterval.

You use it like this:

GSTimeIntervalPicker *picker = [[GSTimeIntervalPicker alloc] init];
picker.maxTimeInterval = (3600 * 3);    // set the limit
picker.minuteInterval = 5;              // the step. Default is 1 min.
picker.timeInterval = (3600 * 1.5);     // 1 h 30 minutes
picker.onTimeIntervalChanged = ^(NSTimeInterval newTimeInterval) {
    // Use the value
};

Available on GitHub under MIT license. Blog post here.