如何从date数组创buildios LocalNotification？

我有一组date

NSArray *datesArray=[NSArray arrayWithObjects: @"2014-09-14 00:00:00",@"2014-08-21 07:12:36",@"2014-08-14 00:00:00",@"2014-07-14 00:00:00",@"2014-06-14 00:00:00",@"2015-01-01 10:00:00",@"2014-06-14 00:00:00",@"2014-05-14 11:24:15", nil]; 

现在我想在数组中可用的date前一天如何实现它？

我正在尝试这个

  NSDateFormatter *Formatter1 = [[NSDateFormatter alloc] init]; [Formatter1 setLocale:[[NSLocale alloc] initWithLocaleIdentifier:NSLocaleIdentifier]]; [Formatter1 setTimeZone:[NSTimeZone timeZoneWithName:@"UTC"]]; [Formatter1 setDateFormat:@"yyyy-MM-dd HH:mm:ss"]; UILocalNotification *localNotif = [[UILocalNotification alloc] init]; NSDate *date1 =[NSDate date]; NSString *string =[Formatter1 stringFromDate:date1]; NSLog(@"sring %@",string); NSDate *todaydate =[Formatter1 dateFromString:string]; NSLog(@"2day date is %@",todaydate); for (int i=0;i<datesArray.count;i++) { NSDate *_date =[Formatter1 dateFromString:[datesArray objectAtIndex:i ]]; NSLog(@"date is %@",_date); if(_date == todaydate){ localNotif.fireDate = _date; localNotif.alertBody = @"festival"; localNotif.alertAction=@"Show me"; localNotif.applicationIconBadgeNumber = 1; localNotif.soundName = UILocalNotificationDefaultSoundName; [[UIApplication sharedApplication] scheduleLocalNotification:localNotif]; } 

Answer 1

您可以使用NSCalendar函数，特别是dateByAddingComponents来减去一天

 NSArray *datesArray = @[@"2014-09-14 00:00:00",@"2014-08-21 07:12:36",@"2014-08-14 00:00:00",@"2014-07-14 00:00:00",@"2014-06-14 00:00:00",@"2015-01-01 10:00:00",@"2014-06-14 00:00:00",@"2014-05-14 11:24:15"]; NSCalendar *calendar = [NSCalendar currentCalendar]; NSDateComponents *dateComponents = [[NSDateComponents alloc] init]; [dateComponents setDay:-1]; NSDateFormatter *Formatter1 = [[NSDateFormatter alloc] init]; [Formatter1 setLocale:[[NSLocale alloc] initWithLocaleIdentifier:NSLocaleIdentifier]]; [Formatter1 setTimeZone:[NSTimeZone timeZoneWithName:@"UTC"]]; [Formatter1 setDateFormat:@"yyyy-MM-dd HH:mm:ss"]; [datesArray enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) { UILocalNotification *localNotif = [[UILocalNotification alloc] init]; localNotif.fireDate = [calendar dateByAddingComponents:dateComponents toDate:[Formatter1 dateFromString:obj] options:0]; localNotif.alertBody = @"festival"; localNotif.alertAction = @"Show me"; localNotif.applicationIconBadgeNumber = 1; localNotif.soundName = UILocalNotificationDefaultSoundName; [[UIApplication sharedApplication] scheduleLocalNotification:localNotif]; }]; 

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