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

我改进了其中一个答案,使它与不同的键盘和不同的文本视图/字段在一个页面上工作:

添加观察员:

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

    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillChange(notification:)), name: UIResponder.keyboardWillChangeFrameNotification, object: nil)

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

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

func keyboardWillChange(notification: NSNotification) {

    if let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
        if YOURTEXTVIEW.isFirstResponder {
            self.view.frame.origin.y = -keyboardSize.height
        }
    }
}

删除观察员:

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

    NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillChangeFrameNotification, object: nil)
    NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillHideNotification, object: nil)
}

其他回答

对我有用

override func viewDidLoad() {

        super.viewDidLoad()

        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)
}

 var isScroll = false


@objc func keyboardWillShow(sender: NSNotification) {
    if( !isScroll  ){
        self.view.frame.origin.y -= 150
        isScroll = true
    }
}
@objc func keyboardWillHide(sender: NSNotification) {
    if( isScroll  ){
        self.view.frame.origin.y += 150
        isScroll = false
    }
}

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)
    }
}

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)
  }
}

这是我的解决方案(实际上这段代码是在你的视图中有几个文本字段的情况下,这也适用于当你有一个文本字段的情况下)

class MyViewController: UIViewController, UITextFieldDelegate {

@IBOutlet weak var firstTextField: UITextField!
@IBOutlet weak var secondTextField: UITextField!

var activeTextField: UITextField!
var viewWasMoved: Bool = false


override func viewDidLoad() {
    super.viewDidLoad()
    NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(PrintViewController.keyboardWillShow(_:)), name: UIKeyboardWillShowNotification, object: nil)
    NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(PrintViewController.keyboardWillHide(_:)), name: UIKeyboardWillHideNotification, object: nil)
}

override func viewDidDisappear(animated: Bool) {
    super.viewWillDisappear(animated)
    NSNotificationCenter.defaultCenter().removeObserver(self)
}

func textFieldDidBeginEditing(textField: UITextField) {
    self.activeTextField = textField
}

func textFieldDidEndEditing(textField: UITextField) {
    self.activeTextField = nil
}

func textFieldShouldReturn(textField: UITextField) -> Bool {
    textField.resignFirstResponder()
    return true
}


func keyboardWillShow(notification: NSNotification) {

    let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue()

    var aRect: CGRect = self.view.frame
    aRect.size.height -= keyboardSize!.height

    let activeTextFieldRect: CGRect? = activeTextField?.frame
    let activeTextFieldOrigin: CGPoint? = activeTextFieldRect?.origin

    if (!CGRectContainsPoint(aRect, activeTextFieldOrigin!)) {
        self.viewWasMoved = true
        self.view.frame.origin.y -= keyboardSize!.height
    } else {
        self.viewWasMoved = false
    }
}

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

这是一个解决方案,不处理从一个textField到另一个切换:

override func viewDidLoad() {
        super.viewDidLoad()
        NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillShow:"), name: UIKeyboardWillShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillHide:"), name: UIKeyboardWillHideNotification, object: nil)            
    }   

func keyboardWillShow(notification: NSNotification) {            
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.CGRectValue() {
        self.view.frame.origin.y -= keyboardSize.height
    }            
}

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

要解决这个问题,将keyboardWillShow/Hide替换为以下两个函数:

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

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

斯威夫特3.0:

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?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
        if self.view.frame.origin.y == 0 {
            self.view.frame.origin.y -= keyboardSize.height
        }
    }        
}

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

斯威夫特4.0:

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?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
        if self.view.frame.origin.y == 0 {
            self.view.frame.origin.y -= keyboardSize.height
        }
    }        
}

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

斯威夫特4.2:

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.origin.y == 0 {
            self.view.frame.origin.y -= keyboardSize.height
        }
    }
}

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