本地通知不会触发后台获取

Question

有人可以看看下面的代码并告诉我为什么本地通知没有解雇。我在XCode中运行应用程序并使用调试选项模拟后台提取，但本地通知不会触发。

- (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);
}

Answer 1

您是否询问用户是否允许推送？

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

Answer 2

使用以下代码检查 RespondToSelector：

，而不是检查设备版本

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