使用键盘

Question

我想在显示键盘时向上移动屏幕，在隐藏键盘时移动到底部。

我使用此代码：

override func viewDidLoad() {
        super.viewDidLoad()

        NotificationCenter.default.addObserver(self, selector: #selector(ViewController.keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(ViewController.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)

}

@objc func keyboardWillShow(notification: NSNotification) {
        if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
            if self.view.frame.origin.y == 0{
                self.view.frame.origin.y -= keyboardSize.height
            }
        }
    }

    @objc func keyboardWillHide(notification: NSNotification) {
        if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
            if self.view.frame.origin.y != 0{
                self.view.frame.origin.y += keyboardSize.height
            }
        }
    }

但我有这个问题：http://gph.is/2AvLo1A

在此屏幕上，我点击textField显示键盘并点击空白区域以隐藏键盘几次。我的屏幕向下爬，黑色背景填满整个屏幕。如何解决？

更新

http://gph.is/2F7nux5

显示键盘后，底部有新的空白区域。如果我滚动，我可以看到它：https://imgur.com/a/fFyEC

Answer 1

将scrollview的底部约束挂钩到superViews的底部并将其拖动为IBOutlet并执行此操作

 @objc func keyboardWillShow(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {

          self.scrollviewBottomCon.constant = keyboardSize.height
          self.view.layoutIfNeeded()
          self.scrollView.scrollRectToVisible((self.textfeild.frame), animated: true)
    }
}

@objc func keyboardWillHide(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {

            self.scrollviewBottomCon.constant = 0

            self.view.layoutIfNeeded()
    }
}

Answer 2

尽量不要上下移动整个视图，而是要移动真正需要移动的组件。我建议使用视图来包含你想要移动的元素。

我有一个用例，我在容器视图下面有一个coupe文本字段和一个提交按钮。当键盘出现时，我希望两个文本字段和按钮上升。这是我处理的方式。

@objc func keyboardWillAppear(_ notification: NSNotification) {
    if let userInfo = notification.userInfo,
        let keyboardFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {

        // Calculate how much to move
        let submitButtonHeight = self.submitButton.frame.size.height
        var submitButtonOrigin = self.view.convert(self.submitButton.frame.origin, from: self.containerView)
        submitButtonOrigin.y = submitButtonOrigin.y + submitButtonHeight + 4.0
        var visibleRect = self.view.frame
        visibleRect.size.height -= keyboardFrame.height

        // If keyboard covers the button, move the container up
        if !visibleRect.contains(submitButtonOrigin) {
            let keyboardMove = submitButtonOrigin.y - visibleRect.size.height
            if keyboardMove > 0 {
                UIView.animate(withDuration: 0.3) {
                    self.containerView.transform = CGAffineTransform(translationX: 0, y: -keyboardMove)
                }
            }
        }
    }
}

@objc func keyboardWillDisappear(_ notification: NSNotification) {
    UIView.animate(withDuration: 0.3) {
        self.containerView.transform = CGAffineTransform.identity
    }
}

这可能是也可能不是您的解决方案，但可以提供另一种选择。