The way to show countdown in UITableViewCells, in each cell countdown should be with different time

Question

    - (void)viewDidLoad {
        [super viewDidLoad];
        tableData = [[NSArray alloc]initWithObjects:@"2018-05-16 06:00:00 p",@"2018-05-16 09:00:00 p",@"2018-05-16 11:00:00 p",@"2018-05-17 02:00:00 a",@"2018-05-17 04:00:00 a",nil];

       currDate = [NSDate date];
        NSDateFormatter *dateFormatter=[[NSDateFormatter alloc] init];
        [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss a"];
        NSLog(@"the current date and time is %@",currDate);

        NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
        [dateFormat setDateFormat:@"YYYY-MM-dd hh:mm:ss a"];
        NSString *fxdDate = @"2018-05-16 07:00:00 a";
        NSDate *StartDate = [ dateFormat dateFromString:[ NSString stringWithFormat:@"%@", fxdDate]];
       for(int i=0;i<tableData.count;i++)
        {

            EndDate = [dateFormat dateFromString:tableData[i]];
            NSDateComponents *components, *components2;
            NSInteger hours, minutesfromStart, minuteFromEnd,secondsFromEnd;

            components = [[NSCalendar currentCalendar] components: NSCalendarUnitDay|NSCalendarUnitHour|NSCalendarUnitMinute fromDate: currDate toDate: StartDate options: 0];
            hours = [components hour];
            minutesfromStart = [ components minute];

            components2 = [[NSCalendar currentCalendar] components: NSCalendarUnitDay|NSCalendarUnitHour|NSCalendarUnitMinute fromDate: currDate toDate: EndDate options: 0];

            minuteFromEnd = [ components2 minute];
            secondsFromEnd = [ components2 second];

            NSDateComponents *components1;
            NSInteger hours1, minutes1, Seconds1;
            components1 = [[NSCalendar currentCalendar] components: 
 NSCalendarUnitDay|NSCalendarUnitHour|NSCalendarUnitMinute|NSCalendarUnitSecond fromDate: currDate toDate: EndDate options: 0];
            hours1 = [components1 hour];
            minutes1 = [ components1 minute];
            Seconds1 = [ components1 second];

            currMinute = minutes1;
            currHours = hours1;
            currSeconds =Seconds1;

            NSLog(@"Time left is %ld:%ld:%ld", (long)hours1, (long)minutes1,(long)Seconds1);

           timer=[NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(timerFired) userInfo:nil repeats:YES];
             }

   -(void)timerFired
{
       if(( currHours>=0 || currMinute >=0 || currSeconds>=0) && currSeconds>=0)
        {
            if(currSeconds==0 && currMinute>0)
            {
                currMinute-=1;
                currSeconds=59;
            }
            else if(currMinute==0 && currHours>0)
            {
                currHours-=1;
                currMinute=59;
            }
            else if(currSeconds>=0)
            {
                currSeconds-=1;
            }
            if(currSeconds>-1)

           [tableview reloadData];

        }


        else
        {
            [timer invalidate];
        }
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *simpleTableIdentifier = @"Reuse";

    SimpleTableViewCell *cell = (SimpleTableViewCell *)[tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];

    if (cell == nil) {

       NSArray *nib =[[NSBundle mainBundle]loadNibNamed:@"SimpleTableViewCell" owner:self options:nil];
        cell=[nib objectAtIndex:0];
    }

    if(indexPath.row == 0)
    {
        cell.dynamicTimerLabel.text =[NSString stringWithFormat:@"%02ld:%02ld:%02ld",currHours,currMinute, currSeconds];



    }

    if(indexPath.row == 1)
    {
        cell.dynamicTimerLabel.text =[NSString stringWithFormat:@"%02ld:%02ld:%02ld",currHours,currMinute, currSeconds];

    }

    if(indexPath.row == 2)
    {
        cell.dynamicTimerLabel.text =[NSString stringWithFormat:@" %02ld:%02ld:%02ld",currHours,currMinute, currSeconds];

    }
    if(indexPath.row == 3)
    {

        cell.dynamicTimerLabel.text =[NSString stringWithFormat:@" %02ld:%02ld:%02ld",currHours,currMinute, currSeconds];

    }
    if(indexPath.row == 4)
    {

        cell.dynamicTimerLabel.text =[NSString stringWithFormat:@" %02ld:%02ld:%02ld",currHours,currMinute, currSeconds];

    }


    cell.TimerLabel.text = [tableData objectAtIndex:indexPath.row];
    return cell;
}

In the above code, it is creating a countdown timer on the UITableView cells but it is only taking the last element of the array for the timer and decrementing the same for each cell but I want it to take each element of the array for each cell. Please HELP. The timer function is getting fired only once.

Answer 1

 if(indexPath.row == 0)
        {
            currDate = [NSDate date];
            NSDateFormatter *dateFormatter=[[NSDateFormatter alloc] init];
            [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss a"];
            NSLog(@"the current date and time is %@",currDate);

            NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
            [dateFormat setDateFormat:@"YYYY-MM-dd hh:mm:ss a"];
            NSString *fxdDate = @"2018-05-16 07:00:00 a";
            NSDate *StartDate = [ dateFormat dateFromString:[ NSString stringWithFormat:@"%@", fxdDate]];

            NSString *dynDate = @"2018-05-17 08:00:00 p";

            EndDate = [dateFormat dateFromString:dynDate];
                NSDateComponents *components, *components2;
                NSInteger hours, minutesfromStart, minuteFromEnd,secondsFromEnd;

                components = [[NSCalendar currentCalendar] components: NSCalendarUnitDay|NSCalendarUnitHour|NSCalendarUnitMinute fromDate: currDate toDate: StartDate options: 0];
                hours = [components hour];
                minutesfromStart = [ components minute];

                components2 = [[NSCalendar currentCalendar] components: NSCalendarUnitDay|NSCalendarUnitHour|NSCalendarUnitMinute fromDate: currDate toDate: EndDate options: 0];

                minuteFromEnd = [ components2 minute];
                secondsFromEnd = [ components2 second];

                NSDateComponents *components1;
                NSInteger hours1, minutes1, Seconds1;

                components1 = [[NSCalendar currentCalendar] components: NSCalendarUnitDay|NSCalendarUnitHour|NSCalendarUnitMinute|NSCalendarUnitSecond fromDate: currDate toDate: EndDate options: 0];
                hours1 = [components1 hour];
                minutes1 = [ components1 minute];
                Seconds1 = [ components1 second];

                currMinute = minutes1;
                currHours = hours1;
                currSeconds =Seconds1;

                NSLog(@"Time left is %ld:%ld:%ld", (long)hours1, (long)minutes1,(long)Seconds1);

              timer=[NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(timerFired) userInfo:nil repeats:YES];

                 cell.dynamicTimerLabel.text =[NSString stringWithFormat:@"%02ld:%02ld:%02ld",currHours,currMinute, currSeconds];


            }





        if(indexPath.row == 1)
        {
            currDate = [NSDate date];
            NSDateFormatter *dateFormatter=[[NSDateFormatter alloc] init];
            [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss a"];
            NSLog(@"the current date and time is %@",currDate);

            NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
            [dateFormat setDateFormat:@"YYYY-MM-dd hh:mm:ss a"];
            NSString *fxdDate = @"2018-05-16 07:00:00 a";
            NSDate *StartDate = [ dateFormat dateFromString:[ NSString stringWithFormat:@"%@", fxdDate]];

            NSString *dynDate = @"2018-05-17 09:00:00 p";

            EndDate = [dateFormat dateFromString:dynDate];
            NSDateComponents *components, *components2;
            NSInteger hours, minutesfromStart, minuteFromEnd,secondsFromEnd;

            components = [[NSCalendar currentCalendar] components: NSCalendarUnitDay|NSCalendarUnitHour|NSCalendarUnitMinute fromDate: currDate toDate: StartDate options: 0];
            hours = [components hour];
            minutesfromStart = [ components minute];

            components2 = [[NSCalendar currentCalendar] components: NSCalendarUnitDay|NSCalendarUnitHour|NSCalendarUnitMinute fromDate: currDate toDate: EndDate options: 0];

            minuteFromEnd = [ components2 minute];
            secondsFromEnd = [ components2 second];

            NSDateComponents *components1;
            NSInteger hours1, minutes1, Seconds1;

            components1 = [[NSCalendar currentCalendar] components: NSCalendarUnitDay|NSCalendarUnitHour|NSCalendarUnitMinute|NSCalendarUnitSecond fromDate: currDate toDate: EndDate options: 0];
            hours1 = [components1 hour];
            minutes1 = [ components1 minute];
            Seconds1 = [ components1 second];

            currMinute = minutes1;
            currHours = hours1;
            currSeconds =Seconds1;

            NSLog(@"Time left is %ld:%ld:%ld", (long)hours1, (long)minutes1,(long)Seconds1);

            timer=[NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(timerFired) userInfo:nil repeats:YES];

            cell.dynamicTimerLabel.text =[NSString stringWithFormat:@"%02ld:%02ld:%02ld",currHours,currMinute, currSeconds];

        }

        if(indexPath.row == 2)
        {
            currDate = [NSDate date];
            NSDateFormatter *dateFormatter=[[NSDateFormatter alloc] init];
            [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss a"];
            NSLog(@"the current date and time is %@",currDate);

            NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
            [dateFormat setDateFormat:@"YYYY-MM-dd hh:mm:ss a"];
            NSString *fxdDate = @"2018-05-16 07:00:00 a";
            NSDate *StartDate = [ dateFormat dateFromString:[ NSString stringWithFormat:@"%@", fxdDate]];

            NSString *dynDate = @"2018-05-17 11:00:00 p";

            EndDate = [dateFormat dateFromString:dynDate];
            NSDateComponents *components, *components2;
            NSInteger hours, minutesfromStart, minuteFromEnd,secondsFromEnd;

            components = [[NSCalendar currentCalendar] components: NSCalendarUnitDay|NSCalendarUnitHour|NSCalendarUnitMinute fromDate: currDate toDate: StartDate options: 0];
            hours = [components hour];
            minutesfromStart = [ components minute];

            components2 = [[NSCalendar currentCalendar] components: NSCalendarUnitDay|NSCalendarUnitHour|NSCalendarUnitMinute fromDate: currDate toDate: EndDate options: 0];

            minuteFromEnd = [ components2 minute];
            secondsFromEnd = [ components2 second];

            NSDateComponents *components1;
            NSInteger hours1, minutes1, Seconds1;

            components1 = [[NSCalendar currentCalendar] components: NSCalendarUnitDay|NSCalendarUnitHour|NSCalendarUnitMinute|NSCalendarUnitSecond fromDate: currDate toDate: EndDate options: 0];
            hours1 = [components1 hour];
            minutes1 = [ components1 minute];
            Seconds1 = [ components1 second];

            currMinute = minutes1;
            currHours = hours1;
            currSeconds =Seconds1;

            NSLog(@"Time left is %ld:%ld:%ld", (long)hours1, (long)minutes1,(long)Seconds1);



         timer=[NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(timerFired) userInfo:nil repeats:YES];



             cell.dynamicTimerLabel.text =[NSString stringWithFormat:@"%02ld:%02ld:%02ld",currHours,currMinute, currSeconds];
        }

        if(indexPath.row == 3)
        {
            currDate = [NSDate date];
            NSDateFormatter *dateFormatter=[[NSDateFormatter alloc] init];
            [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss a"];
            NSLog(@"the current date and time is %@",currDate);

            NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
            [dateFormat setDateFormat:@"YYYY-MM-dd hh:mm:ss a"];
            NSString *fxdDate = @"2018-05-16 07:00:00 a";
            NSDate *StartDate = [ dateFormat dateFromString:[ NSString stringWithFormat:@"%@", fxdDate]];

            NSString *dynDate = @"2018-05-18 02:00:00 a";

            EndDate = [dateFormat dateFromString:dynDate];
            NSDateComponents *components, *components2;
            NSInteger hours, minutesfromStart, minuteFromEnd,secondsFromEnd;

            components = [[NSCalendar currentCalendar] components: NSCalendarUnitDay|NSCalendarUnitHour|NSCalendarUnitMinute fromDate: currDate toDate: StartDate options: 0];
            hours = [components hour];
            minutesfromStart = [ components minute];

            components2 = [[NSCalendar currentCalendar] components: NSCalendarUnitDay|NSCalendarUnitHour|NSCalendarUnitMinute fromDate: currDate toDate: EndDate options: 0];

            minuteFromEnd = [ components2 minute];
            secondsFromEnd = [ components2 second];

            NSDateComponents *components1;
            NSInteger hours1, minutes1, Seconds1;

            components1 = [[NSCalendar currentCalendar] components: NSCalendarUnitDay|NSCalendarUnitHour|NSCalendarUnitMinute|NSCalendarUnitSecond fromDate: currDate toDate: EndDate options: 0];
            hours1 = [components1 hour];
            minutes1 = [ components1 minute];
            Seconds1 = [ components1 second];

            currMinute = minutes1;
            currHours = hours1;
            currSeconds =Seconds1;

            NSLog(@"Time left is %ld:%ld:%ld", (long)hours1, (long)minutes1,(long)Seconds1);

            timer=[NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(timerFired) userInfo:nil repeats:YES];

             cell.dynamicTimerLabel.text =[NSString stringWithFormat:@"%02ld:%02ld:%02ld",currHours,currMinute, currSeconds];
        }

        if(indexPath.row == 4)
        {
            currDate = [NSDate date];
            NSDateFormatter *dateFormatter=[[NSDateFormatter alloc] init];
            [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss a"];
            NSLog(@"the current date and time is %@",currDate);

            NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
            [dateFormat setDateFormat:@"YYYY-MM-dd hh:mm:ss a"];
            NSString *fxdDate = @"2018-05-16 07:00:00 a";
            NSDate *StartDate = [ dateFormat dateFromString:[ NSString stringWithFormat:@"%@", fxdDate]];

            NSString *dynDate = @"2018-05-18 4:00:00 a";

            EndDate = [dateFormat dateFromString:dynDate];
            NSDateComponents *components, *components2;
            NSInteger hours, minutesfromStart, minuteFromEnd,secondsFromEnd;

            components = [[NSCalendar currentCalendar] components: NSCalendarUnitDay|NSCalendarUnitHour|NSCalendarUnitMinute fromDate: currDate toDate: StartDate options: 0];
            hours = [components hour];
            minutesfromStart = [ components minute];

            components2 = [[NSCalendar currentCalendar] components: NSCalendarUnitDay|NSCalendarUnitHour|NSCalendarUnitMinute fromDate: currDate toDate: EndDate options: 0];

            minuteFromEnd = [ components2 minute];
            secondsFromEnd = [ components2 second];

            NSDateComponents *components1;
            NSInteger hours1, minutes1, Seconds1;

            components1 = [[NSCalendar currentCalendar] components: NSCalendarUnitDay|NSCalendarUnitHour|NSCalendarUnitMinute|NSCalendarUnitSecond fromDate: currDate toDate: EndDate options: 0];
            hours1 = [components1 hour];
            minutes1 = [ components1 minute];
            Seconds1 = [ components1 second];

            currMinute = minutes1;
            currHours = hours1;
            currSeconds =Seconds1;

            NSLog(@"Time left is %ld:%ld:%ld", (long)hours1, (long)minutes1,(long)Seconds1);


            timer=[NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(timerFired) userInfo:nil repeats:YES];

             cell.dynamicTimerLabel.text =[NSString stringWithFormat:@"%02ld:%02ld:%02ld",currHours,currMinute, currSeconds];
        }



-(void)timerFired

{

if(( currHours>=0 || currMinute >=0 || currSeconds>=0) && currSeconds>=0)
    {
        if(currSeconds==0 && currMinute>0)
        {
            currMinute-=1;
            currSeconds=59;
        }
        else if(currMinute==0 && currHours>0)
        {
            currHours-=1;
            currMinute=59;
        }
        else if(currSeconds>=0)
        {
            currSeconds-=1;
        }
        if(currSeconds>-1)
            time=[NSString stringWithFormat:@"%02ld:%02ld:%02ld",currHours,currMinute, currSeconds];
            [tableview reloadData];

    }


    else
    {
        [timer invalidate];
    }

}

It worked for me

Answer 2

1) Have your timer fire once per second, which it already does, except all it needs to call is reloadData. 2) Do your time calculations in cellForRowAtIndexPath, and based on the indexPath.row, compute the interval between the destination time for that row, and the current time, then display that interval in hours: minutes: seconds. Currently, your timer is firing, computing one interval, and all the cells are using that interval for their information.

Answer 3

You need to schedule a method to repeatedly trigger after 1 second. And place a currentIndex object at global level and increment it whenever timer method executed.

@interface YourCellClass(){
    NSInteger currentTimerIndex;
    NSTimer *timer;
    NSArray *arrayOfTimes;
    BOOL isTimerCompleted;
}
@property (strong, nonatomic) NSString *dateString;
@end
@implementation YourCellClass
-(void)layoutSubviews {
    [super layoutSubviews];
    //This line will call startTimer function after every 1 second.
    if (!isTimerCompleted && timer == nil) {
        timer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(startTimer) userInfo:nil repeats:YES];
    }
}
-(void)startTimer {

    // dateString should be assign from you cellForRowAtIndexPath method like this
    //cell.dateString = [dateArray objectAtIndexPath:indexPath];


    //Suppose you have pass 16/5/2018 9:12:45 as dateString
    //So below i am checking how much is the difference between providedDate and currentDate with respect to (hours, minuts and seconds)
    // if all get zero it means both dates have become equal so i am disabling the timer.
    // In real scenario its like your order delivery has been set to 9:12:45 and its 8:59:45 now so you have
    // 0 hours 13 minuts and 0 seconds
    // In the very next second your timer have
    // 0 hours 12 minutes and 59 seconds and so on.

    NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
    [dateFormat setDateFormat:@"YYYY-MM-dd hh:mm:ss a"];
    NSString *fxdDate = @"2018-05-16 07:00:00 a";
    NSDate *date = [ dateFormat dateFromString:self.dateString];


    NSDateComponents *components = [[NSCalendar currentCalendar] components: NSCalendarUnitDay|NSCalendarUnitHour|NSCalendarUnitMinute fromDate: NSDate.date toDate: date options: 0];
    if (components.hour == 0 && components.minute == 0 && components.second == 0) {
        [timer invalidate];
        isTimerCompleted = YES;
    }else {
        NSString *newTimeString = [NSString stringWithFormat:@"%ld : %ld : %ld",components.hour,components.minute,components.second];
        //
    }
}