UIMutableUserNotificationAction *notificationAction1 = [[UIMutableUserNotificationAction alloc] init];

    notificationAction1.identifier = @"Accept";

    notificationAction1.title = @"Accept";

    notificationAction1.activationMode = UIUserNotificationActivationModeBackground;

    notificationAction1.destructive = NO;

    notificationAction1.authenticationRequired = NO;

    UIMutableUserNotificationAction *notificationAction2 = [[UIMutableUserNotificationAction alloc] init];

    notificationAction2.identifier = @"Reject";

    notificationAction2.title = @"Reject";

    notificationAction2.activationMode = UIUserNotificationActivationModeBackground;

    notificationAction2.destructive = YES;

    notificationAction2.authenticationRequired = YES;

    UIMutableUserNotificationAction *notificationAction3 = [[UIMutableUserNotificationAction alloc] init];

    notificationAction3.identifier = @"Reply";

    notificationAction3.title = @"Reply";

    notificationAction3.activationMode = UIUserNotificationActivationModeForeground;

    notificationAction3.destructive = NO;

    notificationAction3.authenticationRequired = YES;

    UIMutableUserNotificationCategory *notificationCategory = [[UIMutableUserNotificationCategory alloc] init];

    notificationCategory.identifier = @"Email";

   // [notificationCategory setActions:@[notificationAction3] forContext:UIUserNotificationActionContextDefault];

    [notificationCategory setActions:@[notificationAction1] forContext:UIUserNotificationActionContextMinimal];

    NSSet *categories = [NSSet setWithObjects:notificationCategory, nil];

    UIUserNotificationType notificationType = UIUserNotificationTypeBadge | UIUserNotificationTypeSound | UIUserNotificationTypeAlert;

    UIUserNotificationSettings *notificationSettings = [UIUserNotificationSettings settingsForTypes:notificationType categories:categories];

    [[UIApplication sharedApplication] registerUserNotificationSettings:notificationSettings];

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

    localNotification.fireDate = [NSDate dateWithTimeIntervalSinceNow:];

    localNotification.alertBody = @"Testing";

    localNotification.category = @"Email"; //  Same as category identifier

    [[UIApplication sharedApplication] scheduleLocalNotification:localNotification];

UIUserNotificationActionContextDefault

The default context for displaying the alert. In this context, the full UI is displayed for the notification’s alert. You may specify up to four custom actions in this context.

UIUserNotificationActionContextMinimal

A notification where space is minimal. In this context, a minimal UI is displayed for the notification’s alert. You may specify up to two custom actions in this context.

注意，当应用程序在前台时，通知到来，系统不会为程序弹出alert(共有3中弹出方式，用户可以在settings 中进行设定)，而是会调用相应的didReceiveLocalNotification 和 didReceiveRemoteNotification 这2个代理函数，把通知内容交给程序自身处理。而当程序不在前台时，系统才会为用户弹出alert，提示用户进行相应操作。

另外，点击通知中心的通知时，有2中情况：
一种是程序已经启动了而且不在前台，这时，也会调用didReceiveLocalNotification，那么如何和系统在前台时调用的didReceiveLocalNotification区别呢？（为什么要区别：一般点击notification center后进入程序不弹出alert，而程序在前台时收到通知要弹出alert，这是苹果程序的一般做法）答案是：可以通过UIApplication.sharedApplication().applicationState来区别，当从notification center进来，调用didReceiveLocalNotification时 程序的状态是UIApplicationState.Inactive。
另一种状态是程序没有系统，这时会调用didFinishLaunchingWithOptions函数，把notification通过参数传入，不会调用

didReceiveLocalNotification 了。

。

- (void)application:(UIApplication *)application handleActionWithIdentifier:(NSString *)identifier forLocalNotification:(UILocalNotification *)notification completionHandler:(void (^)())completionHandler 

或者 

- (void)application:(UIApplication *)application handleActionWithIdentifier:(NSString *)identifier forRemoteNotification:(NSDictionary *)userInfo completionHandler:(void(^)())completionHandler NS_AVAILABLE_IOS(8_0);

<Warning>: <BKNewProcess: 0x17e685f0; -.bbbb; pid: ; hostpid: -> has active assertions beyond permitted time:

    {(

        <BKProcessAssertion: 0x17d6b4f0> id: -2B9D290F-7F21-4DCB-955B-9D80DE693382 name: Notification action process: <BKNewProcess: 0x17e685f0; -.bbbb; pid: ; hostpid: -> permittedBackgroundDuration: 30.000000 reason: notificationAction owner pid: preventSuspend  preventThrottleDownUI  preventIdleSleep  preventSuspendOnSleep ,

        <BKProcessAssertion: 0x17d6de50> id: -707C3B54-51BC-47DA-B779-B11888416FE4 name: Deliver Message process: <BKNewProcess: 0x17e685f0; -.bbbb; pid: ; hostpid: -> permittedBackgroundDuration: 10.000000 reason: suspend owner pid: preventSuspend  preventThrottleDownCPU  preventThrottleDownUI  preventSuspendOnSleep

    )}

- (void)application:(UIApplication *)application handleActionWithIdentifier:(NSString *)identifier forLocalNotification:(UILocalNotification *)notification completionHandler:(void (^)())completionHandler 或者 

- (void)application:(UIApplication *)application handleActionWithIdentifier:(NSString *)identifier forRemoteNotification:(NSDictionary *)userInfo completionHandler:(void(^)())completionHandler NS_AVAILABLE_IOS(8_0);