Local Notification Not Firing With Background Fetch

问题

Can someone please take a look at the following code and tell me why the local notification isn't firing. Im running the app in XCode and using the debug option to simulate a background fetch but the local notification doesn't fire.

- (void)application:(UIApplication *)application performFetchWithCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler
 {
     NSLog(@"performFetchWithCompletionHandler");


UILocalNotification *localNotif = [[UILocalNotification alloc] init];

if (localNotif) {
    localNotif.alertBody = @"Update demo text!";
    localNotif.alertAction = @"OK";
    localNotif.soundName = UILocalNotificationDefaultSoundName;
    localNotif.fireDate = nil;

    NSLog(@"Local Notification");

    [[UIApplication sharedApplication] scheduleLocalNotification:localNotif];
}

//Perform some operation
completionHandler(UIBackgroundFetchResultNewData);
}

回答1:

Do you query the user to allow push?

if ([UIDevice currentDevice].systemVersion.floatValue >= 8.0) {
      UIUserNotificationSettings *settings = [UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeBadge | UIUserNotificationTypeAlert | UIUserNotificationTypeSound categories:nil];
      [application registerUserNotificationSettings:settings];
    }

回答2:

Instead of checking device version, use below code that checks RespondToSelector:

if ([UIApplication instancesRespondToSelector:@selector(registerUserNotificationSettings:)])
{
    [application registerUserNotificationSettings:[UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeAlert|UIUserNotificationTypeBadge|UIUserNotificationTypeSound categories:nil]];
}

来源：https://stackoverflow.com/questions/36356310/local-notification-not-firing-with-background-fetch