Timer with Target Day to show Alert - timer

Question

I have an app written here is set a fixed reference Day,after this day i want to get an Alert !
with this code I set the date and time : here Day 3 (Thuesday) and hour 11.
this works great! with an Timer in viewDidload my navigationItem.title shows Day/Hour/Minutes to the target day...
now i will set a Timer to this Day/Time, when i open my app after Thuesday (Wednesday or Thursday) the timer is 0 and the Alert shows!
with :
NSString *currentTimestamp = [NSString stringWithFormat:#"%.f", [resetTime timeIntervalSince1970]];
_epochTimeer.text = currentTimestamp;
i convert the Target time to epoch Time for my timer!
- (void) resetTimer:(id)sender {
NSDate *today = [NSDate date];
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
[gregorian setLocale:[NSLocale currentLocale]];
NSDateComponents *nowComponents = [gregorian components:NSYearCalendarUnit | NSWeekCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit fromDate:today];
[nowComponents setWeekday:3]; //2 = Monday 3 di 4 = mi 5 = do 6 = fr 7 = sa
[nowComponents setWeek: [nowComponents week]+ 1 ]; //Next week [nowComponents week] + 1]
[nowComponents setHour:11]; //8a.m.
[nowComponents setMinute:0];
[nowComponents setSecond:0];
NSDate *resetTime = [gregorian dateFromComponents:nowComponents];
NSDateFormatter *df = [[NSDateFormatter alloc] init];
[df setDateFormat:#"dd-MM-YYYY HH:mm:ss"];
NSDate *date1 = today;
NSDate *date2 = resetTime;
NSTimeInterval interval = [date2 timeIntervalSinceDate:date1];
int days = (int)interval / 86400;
int hours = (interval / 3600)- (days * 24);
int minutes = ((interval / 60) - (days * 24 * 60) -(hours * 60));
int sekunden = (days * 86400) + (hours * 3600) +(minutes * 60);
NSString *timeDiff = [NSString stringWithFormat:#"%02d Tage : %02d Std : %02d Min",days, hours, minutes];
self.navigationItem.title = [NSString stringWithFormat:#"%#",timeDiff];
NSString *currentTimestamp = [NSString stringWithFormat:#"%.f", [resetTime timeIntervalSince1970]];
_epochTimeer.text = currentTimestamp;
NSLog(#"timer: %#",timeDiff);
NSLog(#"timer: %#",currentTimestamp);
}
how can I set my timer with this epoch time or the target Day/time?
i am a beginner with timer and NSDate and I do not understand how I can write the code!
or is there a completely different solution to get my Alert after the Target day when i open my APP!
Thanks Jürgen
Sorry for my bad English ..:-)
Thanks for Helping, i Add your Code and Set the localNotification.fireDate to resetTime:
- (void) resetTimer:(id)sender {
NSDate *today = [NSDate date];
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
[gregorian setLocale:[NSLocale currentLocale]];
NSDateComponents *nowComponents = [gregorian components:NSYearCalendarUnit | NSWeekCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit fromDate:today];
[nowComponents setWeekday:7]; //2 = Monday 3 di 4 = mi 5 = do 6 = fr 7 = sa
[nowComponents setWeek: [nowComponents week]]; //Next week [nowComponents week] + 1]
[nowComponents setHour:9]; //8a.m.
[nowComponents setMinute:25];
[nowComponents setSecond:0];
NSDate *resetTime = [gregorian dateFromComponents:nowComponents];
NSDateFormatter *df = [[NSDateFormatter alloc] init];
[df setDateFormat:#"dd-MM-YYYY HH:mm:ss"];
NSDate *date1 = today;
NSDate *date2 = resetTime;
NSTimeInterval interval = [date2 timeIntervalSinceDate:date1];
int days = (int)interval / 86400;
int hours = (interval / 3600)- (days * 24);
int minutes = ((interval / 60) - (days * 24 * 60) -(hours * 60));
int sekunden = (days * 86400) + (hours * 3600) +(minutes * 60);
NSString *timeDiff = [NSString stringWithFormat:#"%02d Tage : %02d Std : %02d Min",days, hours, minutes];
_showTimer.text = [NSString stringWithFormat:#"%02d",sekunden];
self.navigationItem.title = [NSString stringWithFormat:#"%#",timeDiff];
NSString *currentTimestamp = [NSString stringWithFormat:#"%.f", [resetTime timeIntervalSince1970]];
destinationDate = [NSDate dateWithTimeIntervalSince1970:1425981600];
UILocalNotification *localNotification = [[UILocalNotification alloc] init];
localNotification.fireDate =resetTime;
[[UIApplication sharedApplication] scheduleLocalNotification:localNotification];
NSLog(#"timer: %#",timeDiff);
NSLog(#"timer: %#",currentTimestamp);
}
and this for my Alert :
-(void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)notification
{
// code to display an alert here
SCLAlertView *alert = [[SCLAlertView alloc] init];
alert.backgroundType = Blur;
UIColor *color = [UIColor colorWithRed:52/255.0 green:222/255.0 blue:192/255.0 alpha:255/255.0];
[alert showCustom:self image:[UIImage imageNamed:#"geist"] color:color title:NSLocalizedString(#"Auto Reset", nil) subTitle:NSLocalizedString(#"Automatischer Reset Aktiviert!", nil) closeButtonTitle:#"OK" duration:0.0f];
}
when the time has expired and i start my App ... the Alert is not and it does not happen..
I need to do is activate the Notification somewhere?
thanks
Ok i have added your code now in the AppDelegate.m
-(void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)notification
{
UIAlertView* alert= [[UIAlertView alloc]initWithTitle:#"My App"
message:#"Reset"
delegate:nil
cancelButtonTitle:#"OK"
otherButtonTitles:nil];
[alert show];
}}
now it works, when i start my app the Alert shows, but it Loop Blinking and i can't Klick OK!
what is this now...?

Answer 1

This can be done by using NSLocalNotification
UILocalNotification *localNotification = [[UILocalNotification alloc] init];
localNotification.fireDate =<target date>;
[[UIApplication sharedApplication] scheduleLocalNotification:localNotification];
-(void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)notification
{
// code to display an alert here
}