How to display timer in reverse on a label in xcode? [closed] - ios

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i have a view controller in that i want to display time in reverse order.my default time is 00:59:59? i want output like this (00:58:00,00:57:00,00:56:00,00:30:00)?
int currentTimeInSeconds;
NSTimer *myTimer;
if (!timeLabel)
{
timeLabel =0;
}
if (!myTimer)
{
myTimer = [self createTimer];
}
-(NSTimer *)createTimer
{
return [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:#selector(timerTicked) userInfo:nil repeats:YES];
}
-(void)timerTicked
{
if (currentTimeInSeconds == 0)
{
[myTimer invalidate];
currentTimeInSeconds = 60;
timeLabel.text = [self formattedTime:currentTimeInSeconds];
}
else
{
currentTimeInSeconds--;
self.timeLabel.text = [self formattedTime:currentTimeInSeconds];
}
}
-(NSString *)formattedTime:(int)totalSeconds
{
int seconds = totalSeconds%60;
int minutes = (totalSeconds/60)%60;
int hours = totalSeconds/3600;
return [NSString stringWithFormat:#" %02d:%02d:%02d",hours,minutes,seconds];
}

Answer 1

- (IBAction)btnStart:(id)sender {
timet=[self.txtTime.text integerValue];
self.lblTime.text=[NSString stringWithFormat:#"%lu", (unsigned long)timet];
[NSTimer scheduledTimerWithTimeInterval:timet
target:self
selector:#selector(targetMethod)
userInfo:nil
repeats:NO];
[self time];
}
-(void)time
{
[NSTimer scheduledTimerWithTimeInterval:1
target:self
selector:#selector(targetMethod2)
userInfo:nil
repeats:NO];
}
-(void)targetMethod
{
NSLog(#"STOP");
UIAlertView *alert=[[UIAlertView alloc]initWithTitle:#"Stop" message:#"Time is over" delegate:self cancelButtonTitle:#"Ok" otherButtonTitles:nil];//, nil
[alert show];
}
-(void)targetMethod2
{
if(timet!=0)
{
timet-=1;
NSLog(#"%lu",(unsigned long)timet);
self.lblTime.text=[NSString stringWithFormat:#"%lu",(unsigned long)timet];
[self time];
}
}
- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex
{
if (buttonIndex == 0)
{
self.txtTime.text=nil;
self.lblTime.text=nil;
}
}
---------------- Second code ---------------------
#interface ViewController ()
{
UILabel *progress;
NSTimer *timer;
int currMinute;
int currSeconds;
}
#end
#implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
progress=[[UILabel alloc] initWithFrame:CGRectMake(80, 15, 100, 50)];
progress.textColor=[UIColor redColor];
[progress setText:#"Time : 3:00"];
progress.backgroundColor=[UIColor clearColor];
[self.view addSubview:progress];
currMinute=3;
currSeconds=00;
[self start];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
-(void)start
{
timer=[NSTimer scheduledTimerWithTimeInterval:1 target:self selector:#selector(timerFired) userInfo:nil repeats:YES];
}
-(void)timerFired
{
if((currMinute>0 || currSeconds>=0) && currMinute>=0)
{
if(currSeconds==0)
{
currMinute-=1;
currSeconds=59;
}
else if(currSeconds>0)
{
currSeconds-=1;
}
if(currMinute>-1)
[progress setText:[NSString stringWithFormat:#"%#%d%#%02d",#"Time : ",currMinute,#":",currSeconds]];
}
else
{
[timer invalidate];
}
}

Answer 2

- (IBAction)startCountdown:(id)sender {
//Set up a timer that calls the updateTime method every second to update the label
NSTimer *timer;
timer = [NSTimer scheduledTimerWithTimeInterval:1.0
target:self
selector:#selector(updateCounterLabel)
userInfo:nil
repeats:YES];
}
Every 1 Sec call following function.
-(void)timerTicked
{
NSString *dateString = #"12-12-2015";
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"dd-MM-yyyy"];
NSDate *dateFromString = [[NSDate alloc] init];
dateFromString = [dateFormatter dateFromString:dateString];
NSDate *now = [NSDate date];
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *componentsHours = [calendar components:NSHourCalendarUnit fromDate:now];
NSDateComponents *componentMint = [calendar components:NSMinuteCalendarUnit fromDate:now];
NSDateComponents *componentSec = [calendar components:NSSecondCalendarUnit fromDate:now];
NSCalendar *gregorianCalendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *componentsDaysDiff = [gregorianCalendar components:NSDayCalendarUnit
fromDate:now
toDate:dateFromString
options:0];
long day = (long)componentsDaysDiff.day;
long hours = (long)(24-componentsHours.hour);
long minutes = (long)(60-componentMint.minute);
long sec = (long)(60-componentSec.second);
NSString *strForday = [NSString stringWithFormat:#"%02ld",day];
NSString *strForhours = [NSString stringWithFormat:#"%02ld",hours];
NSString *strForminutes = [NSString stringWithFormat:#"%02ld",minutes];
NSString *strForsec = [NSString stringWithFormat:#"%02ld",sec];
NSLog(#"%# %# %# %# ",strForday,strForhours,strForminutes,strForsec);
if (day == 0 && hours == 0 && minutes == 0 && sec == 0) {
[myTimer invalidate];
}
}