     }
     
     private func loadClassDetail() {
+        
+        ThemeHUD.showActivityIndicator()
+        
         getLiveClassDetail(classId, failureHandler: { (reason, errorMessage) in
             ThemeHUD.hideActivityIndicator()
             defaultFailureHandler(reason, errorMessage: errorMessage)

    // MARK: - Life Cycle
    override func viewDidLoad() {
        super.viewDidLoad()
        
        ThemeHUD.showActivityIndicator()
        
        setupUserInterface()
        loadClassDetail()

        // 验证是否已登陆
        if !MalaUserDefaults.isLogined {
            let loginController = LoginViewController()
            loginController.popAction = { [weak self] in
                self?.loadClassDetail()
            }
            self.present(
                UINavigationController(rootViewController: loginController),
                animated: true,
