iOS set local notification on a specific day

问题

I am sure this question is duplicated somewhere, but I can't find a solution. I am making an app in which one feature allows the user to select the days and times they will receive a local notification.

They can select any time of the day they like, and can toggle the different days of the week (mon, tues, weds etc). The notifications will be sent weekly. I therefore limit the user to creating just 3 notifications - if all 7 days are selected I will set the repeatInterval to daily (one notification). If 6 days are selected for each 3 notifications then I will need an individual notification for each day (totalling 3x6=18 notifications). In all likelihood, only 1 notification will be used so this is fine.

I know how to set an notification for a certain time in the future, but how do I set a notification for say 6pm on a Monday?

Below is my code which I have been using for testing. It sets an alert for 4 seconds in the future (I was calling it from applicationDidEnterBackground).

    NSDateComponents *changeComponent = [[NSDateComponents alloc] init];
    changeComponent.second = 4;

    NSCalendar *theCalendar = [NSCalendar currentCalendar];
    NSDate *itemDate = [theCalendar dateByAddingComponents:changeComponent toDate:[NSDate date] options:0];

    UILocalNotification *localNotif = [[UILocalNotification alloc] init];
    localNotif.fireDate = itemDate;
    localNotif.timeZone = [NSTimeZone defaultTimeZone];
    localNotif.repeatInterval = NSWeekdayCalendarUnit;

回答1:

Exactly the same way you are doing right now, but create a date differently:

NSDateComponents *comps = [[[NSDateComponents alloc] init] autorelease];
[comps setDay:1];
[comps setMonth:1];
[comps setYear:2013];
[comps setHour:10];
[comps setMinute:10];
[comps setSecond:10];
localNotif.fireDate = [[NSCalendar currentCalendar] dateFromComponents:comps];

回答2:

I have also searched about it. Below code work good for me. Pass the week day value 1 to 7 Sunday to Saturday and notification body with action which you want to fire and specify your date then notification will come on that specific day.Hope this help you.

-(void) weekEndNotificationOnWeekday: (int)weekday :(UILocalNotification *)notification : (NSDate*) alramDate
{
    NSCalendar *calendar = [NSCalendar currentCalendar];

    NSDateComponents *componentsForFireDate = [calendar components:(NSYearCalendarUnit | NSWeekCalendarUnit |  NSHourCalendarUnit | NSMinuteCalendarUnit| NSSecondCalendarUnit | NSWeekdayCalendarUnit) fromDate: alramDate];
    [componentsForFireDate setWeekday: weekday] ; //for fixing Sunday
  //   [componentsForFireDate setHour: 20] ; //for fixing 8PM hour
 //    [componentsForFireDate setMinute:0] ;
 //    [componentsForFireDate setSecond:0] ;
    notification.repeatInterval = NSWeekCalendarUnit;
    notification.fireDate=[calendar dateFromComponents:componentsForFireDate];
    [[UIApplication sharedApplication] scheduleLocalNotification:notification];

}

回答3:

I know how to set an notification for a certain time in the future, but how do I set a notification for say 6pm on a Monday?

You can create an NSDate object representing 6pm on the next Monday with the approach showed in How to Get an NSDate for a Specific Day of Week and Time from an Existing NSDate. Then, if you want it to repeat on every Monday you can use localNotification.repeatInterval = NSWeekCalendarUnit. However I'm not sure it's going to work as expected with Daylight saving time.

回答4:

I don't think you can schedule notifications with that much flexibility. Just schedule the next one anytime they change it, and when it fires schedule the next one coming up. Only one to worry about canceling and easy to setup.

来源：https://stackoverflow.com/questions/19276361/ios-set-local-notification-on-a-specific-day

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ios

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uilocalnotification