Swift3.0 Notification 监控键盘的弹出与收回

1.注册／移除通知：

override func viewDidLoad() {

       super.viewDidLoad()

       

       NotificationCenter.default.addObserver(self, selector: #selector(keyBoardWillShow(_:)), name:NSNotification.Name.UIKeyboardWillShow, object: nil)

       NotificationCenter.default.addObserver(self, selector: #selector(keyBoardWillHide(_:)), name:NSNotification.Name.UIKeyboardWillHide, object: nil)

    }

    

    deinit {

       //移除通知

       NotificationCenter.default.removeObserver(self)

    }

2.实现通知的方法：

//键盘的出现

    func keyBoardWillShow(_notification: Notification){

        //获取userInfo

       let kbInfo = notification.userInfo

        //获取键盘的size

       let kbRect =(kbInfo?[UIKeyboardFrameEndUserInfoKey] as! NSValue).cgRectValue

        //键盘的y偏移量

       let changeY = kbRect.origin.y -SCREEN_HEIGHT

        //键盘弹出的时间

       let duration =kbInfo?[UIKeyboardAnimationDurationUserInfoKey] as!Double

       

        //界面偏移动画

       UIView.animate(withDuration: duration) {

           

           self.aTableView.transform= CGAffineTransform(translationX: 0, y:changeY)

       }

    }

    

    //键盘的隐藏

    func keyBoardWillHide(_notification: Notification){

       

       let kbInfo = notification.userInfo

       let kbRect =(kbInfo?[UIKeyboardFrameEndUserInfoKey] as! NSValue).cgRectValue

/*

* let kbRect = (userInfo![UIKeyboardFrameEndUserInfoKey] as AnyObject).cgRectValue

* swift2.3正常，swift3.0取值为nil

*/

       let changeY = kbRect.origin.y

       let duration =kbInfo?[UIKeyboardAnimationDurationUserInfoKey] as!Double

       

       UIView.animate(withDuration: duration) {

           self.tableViewConstraint.update(inset:0)

       }

    }

思路整理：

1.view消失，检查frame的origin

2.第一思路：closure没有捕获变量；错误

  第二思路：notification.userInfo有值；有UIKeyboardFrameEndUserInfoKey键，有value；

查看新的取值方法。