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)
        }
    }

最简单的方法，甚至不需要任何代码:

下载KeyboardLayoutConstraint.swift并将文件添加(拖放)到你的项目中，如果你还没有使用Spring动画框架的话。 在你的故事板中，为视图或文本字段创建一个底部约束，选择约束(双击它)，在标识检查器中，将其类从NSLayoutConstraint更改为KeyboardLayoutConstraint。 完成了!

物体会随着键盘同步自动移动。

类似于@Boris的回答，但在Swift 5中:

override func 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)
}

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

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

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)
}

@Boris的解决方案非常好，但观点有时会被破坏。

为了实现完美的对齐，请使用下面的代码

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)}

功能:

@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
    }
}}    

And,

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

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)
        }
    }