swift之键盘弹起、收起监听事件以及获取键盘高度

添加观察者

NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(_:)),name:UIResponder.keyboardWillShowNotification, object: nil)

NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name: UIResponder.keyboardWillHideNotification, object: nil)

添加监听的方法

@objc func keyboardWillShow(_ sender: Notification) {
    //获取键盘的frame
    guard let keyboardFrame = (sender.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as AnyObject).cgRectValue else {return }
    然后键盘弹起的时候或者改变键盘的时候 就会响应这个方法
}

@objc func keyboardWillHide(_ sender: Notification) {
    然后键盘隐藏的时候就会响应这个方法
}