1.本地通知需要當應用在後臺時執行，比如放在applicationDidEnterBackground方法裡；

2.需要註冊通知

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
	[self notificationSetting];
	return YES;
}

/**
 *推送設定
 */
-(void)notificationSetting{
    // ios8後，需要新增這個註冊，才能得到授權
    if ([[UIApplication sharedApplication] respondsToSelector:@selector(registerUserNotificationSettings:)]) {
        UIUserNotificationType type =  UIUserNotificationTypeAlert | UIUserNotificationTypeBadge | UIUserNotificationTypeSound;
        UIUserNotificationSettings *settings = [UIUserNotificationSettings settingsForTypes:type
                                                                                 categories:nil];
        [[UIApplication sharedApplication] registerUserNotificationSettings:settings];
        
    }
}

- (void)applicationDidEnterBackground:(UIApplication *)application {
    [self execLocalNofitication];
}

-(void)execLocalNofitication{
    UILocalNotification *notification = [[UILocalNotification alloc] init];
    if (notification) {
        // 設定觸發通知的時間
        NSDate *fireDate = [NSDate dateWithTimeIntervalSinceNow:2];
        notification.fireDate = fireDate;
        // 時區
        notification.timeZone = [NSTimeZone defaultTimeZone];
        // 設定重複的間隔
        notification.repeatInterval = 0;
        // 通知內容
        notification.alertBody = nil;
        notification.applicationIconBadgeNumber = -99;
        // 通知被觸發時播放的聲音
        notification.soundName = nil;
        // 執行通知註冊
        [[UIApplication sharedApplication] scheduleLocalNotification:notification];
    }
}