Swift 3

func textFieldDidBeginEditing(_ textField: UITextField) { // became first responder

    //move textfields up
    let myScreenRect: CGRect = UIScreen.main.bounds
    let keyboardHeight : CGFloat = 216

    UIView.beginAnimations( "animateView", context: nil)
    var movementDuration:TimeInterval = 0.35
    var needToMove: CGFloat = 0

    var frame : CGRect = self.view.frame
    if (textField.frame.origin.y + textField.frame.size.height + UIApplication.shared.statusBarFrame.size.height > (myScreenRect.size.height - keyboardHeight - 30)) {
        needToMove = (textField.frame.origin.y + textField.frame.size.height + UIApplication.shared.statusBarFrame.size.height) - (myScreenRect.size.height - keyboardHeight - 30);
    }

    frame.origin.y = -needToMove
    self.view.frame = frame
    UIView.commitAnimations()
}

func textFieldDidEndEditing(_ textField: UITextField) {
    //move textfields back down
    UIView.beginAnimations( "animateView", context: nil)
    var movementDuration:TimeInterval = 0.35
    var frame : CGRect = self.view.frame
    frame.origin.y = 0
    self.view.frame = frame
    UIView.commitAnimations()
}

swift 3.0插入在viewDidLoad()，这->

{

view addSubview (Your_messageInputConteinerView)。

    view.addConstraintWithFormat(format: "H:|[v0]|", views:Your_messageInputConteinerView)

    view.addConstraintWithFormat(format: "V:[v0(48)]", views:Your_messageInputConteinerView)

addobserver (self, selector: #selector(handleKeyboardNotification(notification:)))， name: NSNotification.Name。对象:nil)

addobserver (self, selector: #selector(handleKeyboardNotification(notification:)))，名称:.UIKeyboardWillHide，对象:nil)

bottomConstraint = NSLayoutConstraint(item: Your_messageInputConteinerView, attribute: .bottom, relatedBy: .equal, toItem: view, attribute: .bottom, multiplier: 1, constant: 0)

view.addConstraint(bottomConstraint!)

}

func handleKeyboardNotification(通知:通知){

if let userInfo = notification.userInfo {

    if let keyBoardFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue{

        print(keyBoardFrame)

        if bottomConstraint?.constant != CGFloat(0) {
                bottomConstraint?.constant = 0
                return
            }
     bottomConstraint?.constant = -keyBoardFrame.height
                           or
        self.view.frame.origin.y = -keyBoardFrame.height
    }
}

}

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
    }
}

Swift 3更新…

正如其他人所说，你需要在控制器的viewDidLoad()方法中添加通知观察者，如下所示:

NotificationCenter.default.addObserver(forName: .UIKeyboardWillShow, object: nil, queue: nil)
    { notification in
    self.keyboardWillShow(notification)
    }

NotificationCenter.default.addObserver(forName: .UIKeyboardWillHide, object: nil, queue: nil)
    { notification in
    self.keyboardWillHide(notification)
    }

NotificationCenter.default.addObserver(forName: .UIKeyboardDidShow, object: nil, queue: nil)
    { _ in
    self.enableUserInteraction()
    }

NotificationCenter.default.addObserver(forName: .UIKeyboardDidHide, object: nil, queue: nil)
    { _ in
    self.enableUserInteraction()
    }

记得在适当的地方删除你的观察器(我在viewWillDisappear()方法中这样做)

NotificationCenter.default.removeObserver(self, name: .UIKeyboardWillShow, object: nil)
NotificationCenter.default.removeObserver(self, name: .UIKeyboardWillHide, object: nil)
NotificationCenter.default.removeObserver(self, name: .UIKeyboardDidShow, object: nil)
NotificationCenter.default.removeObserver(self, name: .UIKeyboardDidHide, object: nil)

然后，实现你的show和hide方法——注意告诉应用程序忽略交互事件的行(beginIgnoringInteractionEvents)。这很重要，因为如果没有它，用户可能会点击一个字段甚至滚动视图，导致第二次发生移位，从而导致可怕的UI故障。在键盘显示和隐藏之前忽略交互事件将防止这种情况:

func keyboardWillShow(notification: Notification)
    {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue
        {
        UIApplication.shared.beginIgnoringInteractionEvents()
        self.view.frame.origin.y -= keyboardSize.height
        // add this line if you are shifting a scrollView, as in a chat application
        self.timelineCollectionView.contentInset.top += keyboardSize.height
        }
    }

func keyboardWillHide(notification: Notification)
    {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue
        {
        UIApplication.shared.beginIgnoringInteractionEvents()
        self.view.frame.origin.y += keyboardSize.height
        // add this line if you are shifting a scrollView, as in a chat application
        self.timelineCollectionView.contentInset.top -= keyboardSize.height
        }
    }

最后，重新启用用户交互(记住，这个方法在键盘didShow或didHide之后触发):

func enableUserInteraction()
    {
    UIApplication.shared.endIgnoringInteractionEvents()
    }

斯威夫特4:

我有一个问题与最接受的答案，其中隐藏键盘并没有返回视图一直到页面的底部(只是部分)。这对我来说很有效(+为Swift 4更新)。

override func viewDidLoad() {
    super.viewDidLoad()
    self.hideKeyboardWhenTappedAround()
    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)
}

@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 = 0
        }
    }
}

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()
}