     let seccodeImageView = UIImageView(image: nil)
     let seccodeField = UITextField(frame: CGRect.zero)
 
+    let visibleLayoutGuide = UIView(frame: CGRect.zero)
+
     var dynamicAnimator: UIDynamicAnimator?
     var snapBehavior: UISnapBehavior?
     var dynamicItemBehavior: UIDynamicItemBehavior?

            make.width.equalTo(self.usernameField.snp_width).offset(10.0)
        }

        state = self.inLoginState() ? .Login : .NotLogin

        let tapGesture = UITapGestureRecognizer(target: self, action: #selector(S1LoginViewController.dismiss))

        let dragGesture = UIPanGestureRecognizer(target: self, action: #selector(S1LoginViewController.pan(_:)))
        self.view.addGestureRecognizer(dragGesture)
        self.dragGesture = dragGesture

        NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(S1LoginViewController.keyboardFrameWillChange(_:)), name: UIKeyboardWillChangeFrameNotification, object: nil)
    }

    deinit {
        NSNotificationCenter.defaultCenter().removeObserver(self)
    }

    override func viewDidLayoutSubviews() {
