ios程序后台继续运行

if ([[UIDevice currentDevice].systemVersion doubleValue] >= 8.0) {
            UIUserNotificationType myType = UIRemoteNotificationTypeBadge | UIRemoteNotificationTypeAlert | UIRemoteNotificationTypeSound;
            UIUserNotificationSettings *mySetting = [UIUserNotificationSettings settingsForTypes:myType categories:nil];
            [[UIApplication sharedApplication] registerUserNotificationSettings:mySetting];
        }else{
            UIRemoteNotificationType myType = UIRemoteNotificationTypeBadge | UIRemoteNotificationTypeAlert | UIRemoteNotificationTypeSound;
            [[UIApplication sharedApplication] registerForRemoteNotificationTypes:myType];
        }
        
        [UIApplication sharedApplication].applicationIconBadgeNumber = result.status;//后台运行，有新消息，就在图标的右上角显示个数

/**
 *  程序进入后台的时候调用
 */
- (void)applicationDidEnterBackground:(UIApplication *)application {
    // 提醒操作系统：当前这个应用程序需要在后台开启一个任务
    // 操作系统会允许这个应用程序在后台保持运行状态（能够持续的时间是不确定）
    UIBackgroundTaskIdentifier taskID = [application beginBackgroundTaskWithExpirationHandler:^{
        // 后台运行的时间到期了，就会自动调用这个block
        [application endBackgroundTask:taskID];
    }];

}