Apple watch 真机测试，发现收到的通知没有显示自定义的 action 按钮，请大牛过来诊断一下

(void )registerSettingsAndCategories {
// Create a mutable set to store the category definitions.
NSMutableSet* categories = [NSMutableSet set];

// Define the actions for a meeting invite notification.
UIMutableUserNotificationAction* acceptAction = [[UIMutableUserNotificationAction alloc] init];
acceptAction.title = NSLocalizedString (@"Accept", @"Accept invitation");
acceptAction.identifier = @"accept";
acceptAction.activationMode = UIUserNotificationActivationModeBackground;
acceptAction.authenticationRequired = NO;

UIMutableUserNotificationAction* declineAction = [[UIMutableUserNotificationAction alloc] init];
declineAction.title = NSLocalizedString (@"Decline", @"Decline invitation");
declineAction.identifier = @"decline";
declineAction.activationMode = UIUserNotificationActivationModeBackground;
declineAction.authenticationRequired = NO;

// Create the category object and add it to the set.
UIMutableUserNotificationCategory* inviteCategory = [[UIMutableUserNotificationCategory alloc] init];
[inviteCategory setActions:@[acceptAction, declineAction]
forContext:UIUserNotificationActionContextDefault];
inviteCategory.identifier = @"invitation";

[categories addObject:inviteCategory];

// Configure other actions and categories and add them to the set...

UIUserNotificationSettings* settings = [UIUserNotificationSettings settingsForTypes:
(UIUserNotificationTypeAlert | UIUserNotificationTypeBadge | UIUserNotificationTypeSound )
categories:categories];

[[UIApplication sharedApplication] registerUserNotificationSettings:settings];
}

上述代码是在 appdelegate 中的
- (BOOL )application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions 调用的。

但 watch 中收到的消息死活不显示这两个按钮，就只有一个默认的关闭。

说明： ios 开发新手。服务器推送过来的消息格式没有变过（不知道这里有没有要求），只是现在加了 watch 应用，多了一个展示的途径。
关于这个问题也是找了很多资料，但是一直无法解决，不是伸手党。看了网易新闻的通知，是带有自定义按钮的。说明是我某个地方处理不当引起的。但是因为经验不足，无法准确定位以及解决。所以请大家指点一下。

类似问题： http://stackoverflow.com/questions/30255063/watchkit-simulator-actions-not-working-on-actual-apple-watch-device