我有一个应用,它在视图的下半部分有一个文本框。 这意味着当我在文本框中输入时,键盘会覆盖文本框。

我如何在打字时向上移动视图,这样我就可以看到我键入的内容,然后在键盘消失时将它移回原来的位置?

我到处都看了,但所有的解似乎都在Obj-C中,我还不能完全转换。

任何帮助都将不胜感激。


当前回答

func keyboardWillShow(notification: NSNotification) {

    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
        self.view.frame.origin.y = self.view.frame.height - (self.view.frame.height + keyboardSize.height)
    }

}

func keyboardWillHide(notification: NSNotification) {
        self.view.frame.origin.y = 0
}

它必须更加稳定

其他回答

移动视图的原点是一种幼稚的方法。

这里有一个更好的解决方案:当键盘出现时调整视图的高度。

let viewHeight = self.view.frame.height

    override func viewDidLoad() {
        super.viewDidLoad()

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

    @objc func keyboardWillShow(notification: NSNotification) {
        if let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
            if self.view.frame.height == self.viewHeight{
                self.view.frame = CGRect(x: 0, y: 0, width: self.view.frame.width, height: self.view.frame.height - keyboardSize.height)
            }

        }
    }

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

            self.view.frame = CGRect(x: 0, y: 0, width: self.view.frame.width, height: self.view.frame.height + keyboardSize.height)
        }
    }

对于Swift 3,我做了一个UIViewController子类,因为我需要在所有的视图控制器中恒定的行为。

class SomeClassVC: UIViewController {

  //MARK: - Lifecycle
  override func viewDidLoad() {
    super.viewDidLoad()

    addKeyboardObservers()
  }

  override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)

    removeKeyboardObservers()
  }

  //MARK: - Overrides
  override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    view.endEditing(true)
  }

  //MARK: - Help
  func addKeyboardObservers() {
    NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
  }

  func removeKeyboardObservers() {
    NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillShow, object: self.view.window)
    NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillHide, object: self.view.window)
  }

  func keyboardWillShow(notification: NSNotification) {
    let keyboardHeight = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue.height
    UIView.animate(withDuration: 0.1, animations: { () -> Void in
      self.view.window?.frame.origin.y = -1 * keyboardHeight!
      self.view.layoutIfNeeded()
    })
  }

  func keyboardWillHide(notification: NSNotification) {
    UIView.animate(withDuration: 0.1, animations: { () -> Void in
      self.view.window?.frame.origin.y = 0
      self.view.layoutIfNeeded()
    })
  }

  func resignTextFieldFirstResponders() {
    for textField in self.view.subviews where textField is UITextField {
      textField.resignFirstResponder()
    }
  }

  func resignAllFirstResponders() {
      view.endEditing(true)
  }
}

我注意到其他答案涉及从视图中删除一些顶部。如果你想简单地调整视图的大小而不削减任何内容,只需尝试这个方法:)

func keyboardWillShow(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
        self.view.setTranslatesAutoresizingMaskIntoConstraints(true)
        self.view.frame = CGRectMake(self.view.frame.origin.x, self.view.frame.origin.y, self.view.frame.size.width, self.view.frame.height - keyboardSize.height)
    }
}

func keyboardWillHide(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
        self.collectionView.setTranslatesAutoresizingMaskIntoConstraints(false)
        self.view.frame = CGRectMake(self.view.frame.origin.x, self.view.frame.origin.y, self.view.frame.size.width, self.view.frame.height + keyboardSize.height)
    }
}

验证的答案没有考虑到文本字段的位置,并有一些错误(双位移,永远不会回到主位置,位移即使文本字段是在视图的顶部…)

这个想法是:

获取焦点TextField的Y的绝对位置 来获取键盘高度 来获取屏幕高度 然后计算键盘位置和文本框之间的距离(如果< 0 ->向上移动视图) 使用UIView。而不是UIView.frame.origin.y -= ..,因为用UIView更容易回到原来的位置。变换= .identity

然后,我们将能够移动视图,只有在必要和特定的位移,以便有聚焦texField刚刚超过键盘

代码如下:

斯威夫特4

class ViewController: UIViewController, UITextFieldDelegate {

var textFieldRealYPosition: CGFloat = 0.0

override func viewDidLoad() {
    super.viewDidLoad()

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

  // Delegate all textfields

}


@objc func keyboardWillShow(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
        let distanceBetweenTextfielAndKeyboard = self.view.frame.height - textFieldRealYPosition - keyboardSize.height
        if distanceBetweenTextfielAndKeyboard < 0 {
            UIView.animate(withDuration: 0.4) {
                self.view.transform = CGAffineTransform(translationX: 0.0, y: distanceBetweenTextfielAndKeyboard)
            }
        }
    }
}


@objc func keyboardWillHide(notification: NSNotification) {
    UIView.animate(withDuration: 0.4) {
        self.view.transform = .identity
    }
}


func textFieldDidBeginEditing(_ textField: UITextField) {
  textFieldRealYPosition = textField.frame.origin.y + textField.frame.height
  //take in account all superviews from textfield and potential contentOffset if you are using tableview to calculate the real position
}

}

func keyboardWillShow(notification: NSNotification) {

    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
        self.view.frame.origin.y = self.view.frame.height - (self.view.frame.height + keyboardSize.height)
    }

}

func keyboardWillHide(notification: NSNotification) {
        self.view.frame.origin.y = 0
}

它必须更加稳定