斯威夫特5.0:

经过4-5个小时的战斗，我得到了一个简单的扩展UIViewController与简单的代码，就像魅力

*当TextField在键盘上方时，视图不应该移动

*不需要设置常量值为NSLayoutConstraint

*无需第三方库

*无需动画代码

*适用于tableview

*这适用于自动布局/自动调整大小

extension UIViewController {
    func addKeyboardObserver() {
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardNotifications(notification:)),
                                               name: UIResponder.keyboardWillChangeFrameNotification,
                                               object: nil)
    }

    func removeKeyboardObserver(){
        NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillChangeFrameNotification, object: nil)
    }

    // This method will notify when keyboard appears/ dissapears
    @objc func keyboardNotifications(notification: NSNotification) {

        var txtFieldY : CGFloat = 0.0  //Using this we will calculate the selected textFields Y Position
        let spaceBetweenTxtFieldAndKeyboard : CGFloat = 5.0 //Specify the space between textfield and keyboard


        var frame = CGRect(x: 0, y: 0, width: 0, height: 0)
        if let activeTextField = UIResponder.currentFirst() as? UITextField ?? UIResponder.currentFirst() as? UITextView {
            // Here we will get accurate frame of textField which is selected if there are multiple textfields
            frame = self.view.convert(activeTextField.frame, from:activeTextField.superview)
            txtFieldY = frame.origin.y + frame.size.height
        }

        if let userInfo = notification.userInfo {
            // here we will get frame of keyBoard (i.e. x, y, width, height)
            let keyBoardFrame = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue
            let keyBoardFrameY = keyBoardFrame!.origin.y
            let keyBoardFrameHeight = keyBoardFrame!.size.height

            var viewOriginY: CGFloat = 0.0
            //Check keyboards Y position and according to that move view up and down
            if keyBoardFrameY >= UIScreen.main.bounds.size.height {
                viewOriginY = 0.0
            } else {
                // if textfields y is greater than keyboards y then only move View to up
                if txtFieldY >= keyBoardFrameY {

                    viewOriginY = (txtFieldY - keyBoardFrameY) + spaceBetweenTxtFieldAndKeyboard

                    //This condition is just to check viewOriginY should not be greator than keyboard height
                    // if its more than keyboard height then there will be black space on the top of keyboard.
                    if viewOriginY > keyBoardFrameHeight { viewOriginY = keyBoardFrameHeight }
                }
            }

            //set the Y position of view
            self.view.frame.origin.y = -viewOriginY
        }
    }
}

添加这个扩展的UIResponder得到哪个TextField被选中

extension UIResponder {

    static weak var responder: UIResponder?

    static func currentFirst() -> UIResponder? {
        responder = nil
        UIApplication.shared.sendAction(#selector(trap), to: nil, from: nil, for: nil)
        return responder
    }

    @objc private func trap() {
        UIResponder.responder = self
    }
}

然后在你的任何ViewController中使用这个

   override func viewWillAppear(_ animated: Bool) {
        self.addKeyboardObserver()
    }

    override func viewWillDisappear(_ animated: Bool) {
        self.removeKeyboardObserver()
    }

在func viewWillAppear中注册这个通知(_ animated: Bool) 在func中注销此通知viewWillDisappear(_ animated:Bool) 下载演示文件

在这个线程中，一个流行的答案使用了以下代码:

func keyboardWillShow(sender: NSNotification) {
    self.view.frame.origin.y -= 150
}
func keyboardWillHide(sender: NSNotification) {
    self.view.frame.origin.y += 150
}

用一个静态量来抵消你的视图有一个明显的问题。它在一个设备上看起来很好，但在任何其他尺寸配置上看起来都很糟糕。您需要获取键盘高度并将其用作偏移值。

下面是一种适用于所有设备的解决方案，它可以处理用户在输入时隐藏预测文本字段的边缘情况。

解决方案

下面需要注意的是，我们将self.view.window作为对象参数传入。这将为我们提供来自键盘的数据，比如它的高度!

@IBOutlet weak var messageField: UITextField!

override func viewDidLoad() {
    super.viewDidLoad()

    NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillShow:"), name:UIKeyboardWillShowNotification, object: self.view.window)
    NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillHide:"), name:UIKeyboardWillHideNotification, object: self.view.window)
}

func keyboardWillHide(sender: NSNotification) {
    let userInfo: [NSObject : AnyObject] = sender.userInfo!
    let keyboardSize: CGSize = userInfo[UIKeyboardFrameBeginUserInfoKey]!.CGRectValue.size
    self.view.frame.origin.y += keyboardSize.height
}

我们将使它在所有设备上看起来都很漂亮，并处理用户添加或删除预测文本字段的情况。

func keyboardWillShow(sender: NSNotification) {
    let userInfo: [NSObject : AnyObject] = sender.userInfo!
    let keyboardSize: CGSize = userInfo[UIKeyboardFrameBeginUserInfoKey]!.CGRectValue.size
    let offset: CGSize = userInfo[UIKeyboardFrameEndUserInfoKey]!.CGRectValue.size

    if keyboardSize.height == offset.height {
        UIView.animateWithDuration(0.1, animations: { () -> Void in
            self.view.frame.origin.y -= keyboardSize.height
        })
    } else {
        UIView.animateWithDuration(0.1, animations: { () -> Void in
            self.view.frame.origin.y += keyboardSize.height - offset.height
        })
    }
}

删除观察者

不要忘记在离开视图之前删除您的观察器，以防止传输不必要的消息。

override func viewWillDisappear(animated: Bool) {
    NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillShowNotification, object: self.view.window)
    NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillHideNotification, object: self.view.window)
}

根据评论中的问题更新:

如果你有两个或更多的文本字段，你可以检查你的view.frame.origin.y是否为零。

func keyboardWillShow(sender: NSNotification) {
    let userInfo: [NSObject : AnyObject] = sender.userInfo!

    let keyboardSize: CGSize = userInfo[UIKeyboardFrameBeginUserInfoKey]!.CGRectValue.size
    let offset: CGSize = userInfo[UIKeyboardFrameEndUserInfoKey]!.CGRectValue.size

    if keyboardSize.height == offset.height {
        if self.view.frame.origin.y == 0 {
            UIView.animateWithDuration(0.1, animations: { () -> Void in
                self.view.frame.origin.y -= keyboardSize.height
            })
        }
    } else {
        UIView.animateWithDuration(0.1, animations: { () -> Void in
            self.view.frame.origin.y += keyboardSize.height - offset.height
        })
    }
     print(self.view.frame.origin.y)
}

func registerForKeyboardNotifications()
    {
        //Keyboard
        NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(keyboardWasShown), name: UIKeyboardDidShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(keyboardWillBeHidden), name: UIKeyboardDidHideNotification, object: nil)


    }
    func deregisterFromKeyboardNotifications(){

        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillHideNotification, object: nil)

    }
    func keyboardWasShown(notification: NSNotification){

        let userInfo: NSDictionary = notification.userInfo!
        let keyboardInfoFrame = userInfo.objectForKey(UIKeyboardFrameEndUserInfoKey)?.CGRectValue()

        let windowFrame:CGRect = (UIApplication.sharedApplication().keyWindow!.convertRect(self.view.frame, fromView:self.view))

        let keyboardFrame = CGRectIntersection(windowFrame, keyboardInfoFrame!)

        let coveredFrame = UIApplication.sharedApplication().keyWindow!.convertRect(keyboardFrame, toView:self.view)

        let contentInsets = UIEdgeInsetsMake(0, 0, (coveredFrame.size.height), 0.0)
        self.scrollViewInAddCase .contentInset = contentInsets;
        self.scrollViewInAddCase.scrollIndicatorInsets = contentInsets;
        self.scrollViewInAddCase.contentSize = CGSizeMake((self.scrollViewInAddCase.contentSize.width), (self.scrollViewInAddCase.contentSize.height))

    }
    /**
     this method will fire when keyboard was hidden

     - parameter notification: contains keyboard details
     */
    func keyboardWillBeHidden (notification: NSNotification) {

        self.scrollViewInAddCase.contentInset = UIEdgeInsetsZero
        self.scrollViewInAddCase.scrollIndicatorInsets = UIEdgeInsetsZero

    }

这个实现(Swift 4)将给你的行为最接近Android的默认行为。Ie:当活动文本域在键盘下时，将视图向上移动，当用户切换到另一个视图时，无需关闭键盘。记住调用settextfielddelegate()。

public class DelegateProxy: NSObject, UITextFieldDelegate {

  private static let instance = DelegateProxies()

  weak var activeTextField: UITextField?
  var offset: CGFloat = 0
  weak var vc: UIViewController?
  var keyboardHeight: CGFloat = 0

  public static func getDelegate(root: UIViewController) -> DelegateProxies {
    instance.vc = root
    return instance
  }

  public static func getDelegate() -> DelegateProxies {
    return instance
  }

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


  public func textFieldShouldBeginEditing(_ textField: UITextField) -> Bool {

    self.activeTextField = textField

    let globalPointY: CGFloat = (textField.superview?.convert(textField.frame.origin, to: nil).y ?? CGFloat(0)) + textField.frame.height


    offset = UIScreen.main.bounds.height - globalPointY

    if keyboardHeight > 0 {
        vc?.moveViewUp(offsetFromKeyboard: keyboardHeight - offset)
    }

    return true
  }
}


extension UIViewController {

  private func setTextFieldDelegates(parentView: UIView) {
    for child in parentView.subviews {
        setTextFieldDelegates(parentView: child)
        (child as? UITextField)?.delegate = DelegateProxies.getDelegate(root: self)
    }
  }

  func registerAutoResizeOnKeyboardAppear(){
    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)
  }

  func unregisterAutoResizeOnKeyboard(){
    NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillShow, object: nil)
    NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillHide, object: nil)
  }

  @objc func keyboardWillShow(notification: NSNotification) {

    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
        let offsetFromKeyboard = keyboardSize.height - DelegateProxies.getDelegate().offset
        DelegateProxies.getDelegate().keyboardHeight = keyboardSize.height

        moveViewUp(offsetFromKeyboard: offsetFromKeyboard)
    }
  }

  func moveViewUp(offsetFromKeyboard: CGFloat){
    print("offset from keyboard: \(offsetFromKeyboard)")

    let moveOffset = offsetFromKeyboard + 8

    if offsetFromKeyboard > 0 {
        self.view.frame.origin.y = -moveOffset
    }

    if offsetFromKeyboard < 0 && view.frame.origin.y < 0 {
        self.view.frame.origin.y += -moveOffset
        if self.view.frame.origin.y > 0{
            self.view.frame.origin.y = 0
        }
    }
  }

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

我们对KeyboardWillHideNotification的定义做了一些改变。

此解决方案适用于Swift 4.2:

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


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

@objc func keyboardWillHide(_ notification:Notification) {
    if let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
        self.view.frame.origin.y += keyboardSize.height
    }
}

使用以下代码查看UITextField单击

func textFieldDidBeginEditing(textField: UITextField) {
    ViewUpanimateMoving(true, upValue: 100)
}
func textFieldDidEndEditing(textField: UITextField) {
    ViewUpanimateMoving(false, upValue: 100)
}
func ViewUpanimateMoving (up:Bool, upValue :CGFloat){
    var durationMovement:NSTimeInterval = 0.3
    var movement:CGFloat = ( up ? -upValue : upValue)
    UIView.beginAnimations( "animateView", context: nil)
    UIView.setAnimationBeginsFromCurrentState(true)
    UIView.setAnimationDuration(durationMovement)
    self.view.frame = CGRectOffset(self.view.frame, 0,  movement)
    UIView.commitAnimations()
}