非常简单，不需要编写更多代码。 只需在podfile中添加pod 'IQKeyboardManagerSwift'，并在AppDelegate页面中添加下面的代码。

import IQKeyboardManagerSwift

在方法didFinishLaunchingWithOptions()类型中

IQKeyboardManager.shared.enable = true

就是这样。 查看这个视频链接，以更好地了解https://youtu.be/eOM94K1ZWN8 希望这对你有所帮助。

以下是我对Swift 2.2的解决方案:

首先注册键盘显示/隐藏通知

NSNotificationCenter.defaultCenter().addObserver(self,
                                                 selector: #selector(MessageThreadVC.keyboardWillShow(_:)),
                                                 name: UIKeyboardWillShowNotification,
                                                 object: nil)
NSNotificationCenter.defaultCenter().addObserver(self,
                                                 selector: #selector(MessageThreadVC.keyboardWillHide(_:)),
                                                 name: UIKeyboardWillHideNotification,
                                                 object: nil)

然后在与这些通知相对应的方法中，向上或向下移动主视图

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

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

诀窍在于“keyboardWillShow”部分，每次“QuickType建议栏”被展开或折叠时，该部分都会被调用。然后我们总是设置主视图的y坐标等于键盘总高度的负值(包括或不包括“QuickType栏”部分)。

最后不要忘记删除观察者

deinit {
NSNotificationCenter.defaultCenter().removeObserver(self)
}

另一个解决方案，不依赖于自动布局，约束或任何出口。您所需要的是滚动视图中的字段。

override func viewDidLoad() {
    super.viewDidLoad()

    NSNotificationCenter.defaultCenter().addObserver(self, selector: "makeSpaceForKeyboard:", name: UIKeyboardWillShowNotification, object: nil)
    NSNotificationCenter.defaultCenter().addObserver(self, selector: "makeSpaceForKeyboard:", name: UIKeyboardWillHideNotification, object: nil)
}

func makeSpaceForKeyboard(notification: NSNotification) {
    let info = notification.userInfo!
    let keyboardHeight:CGFloat = (info[UIKeyboardFrameEndUserInfoKey] as! NSValue).CGRectValue().size.height
    let duration:Double = info[UIKeyboardAnimationDurationUserInfoKey] as! Double

    if notification.name == UIKeyboardWillShowNotification {
        UIView.animateWithDuration(duration, animations: { () -> Void in
            var frame = self.view.frame
            frame.size.height = frame.size.height - keyboardHeight
            self.view.frame = frame
        })
    } else {
        UIView.animateWithDuration(duration, animations: { () -> Void in
            var frame = self.view.frame
            frame.size.height = frame.size.height + keyboardHeight
            self.view.frame = frame
        })
    }

}

Swift 5解决方案frédéric-adda:

protocol KeyboardHandler: class {
    var bottomConstraint: NSLayoutConstraint! { get set }
    
    func keyboardWillShow(_ notification: Notification)
    func keyboardWillHide(_ notification: Notification)
    func startObservingKeyboardChanges()
    func stopObservingKeyboardChanges()
}


extension KeyboardHandler where Self: UIViewController {

    func startObservingKeyboardChanges() {

        // NotificationCenter observers
        NotificationCenter.default.addObserver(forName: UIResponder.keyboardWillShowNotification, object: nil, queue: nil) { [weak self] notification in
          self?.keyboardWillShow(notification)
        }

        // Deal with rotations
        NotificationCenter.default.addObserver(forName: UIResponder.keyboardWillChangeFrameNotification, object: nil, queue: nil) { [weak self] notification in
          self?.keyboardWillShow(notification)
        }

        // Deal with keyboard change (emoji, numerical, etc.)
        NotificationCenter.default.addObserver(forName: UITextInputMode.currentInputModeDidChangeNotification, object: nil, queue: nil) { [weak self] notification in
          self?.keyboardWillShow(notification)
        }

        NotificationCenter.default.addObserver(forName: UIResponder.keyboardWillHideNotification, object: nil, queue: nil) { [weak self] notification in
          self?.keyboardWillHide(notification)
        }
    }


    func keyboardWillShow(_ notification: Notification) {

      let verticalPadding: CGFloat = 20 // Padding between the bottom of the view and the top of the keyboard

        guard let value = notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue else { return }
      let keyboardHeight = value.cgRectValue.height

      // Here you could have more complex rules, like checking if the textField currently selected is actually covered by the keyboard, but that's out of this scope.
      self.bottomConstraint.constant = keyboardHeight + verticalPadding

      UIView.animate(withDuration: 0.1, animations: { () -> Void in
          self.view.layoutIfNeeded()
      })
  }


  func keyboardWillHide(_ notification: Notification) {
      self.bottomConstraint.constant = 0

      UIView.animate(withDuration: 0.1, animations: { () -> Void in
          self.view.layoutIfNeeded()
      })
  }


  func stopObservingKeyboardChanges() {
      NotificationCenter.default.removeObserver(self)
  }
}

在任何UIViewController中:

遵循KeyboardHandler协议

extension AnyViewController: KeyboardHandler {} 

为屏幕上最后一个底部元素添加底部约束。

@IBOutlet var bottomConstraint: NSLayoutConstraint! 

添加观察者订阅/取消订阅:

 override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        startObservingKeyboardChanges()
 }
    
 override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        stopObservingKeyboardChanges()
 }

享受吧!

我喜欢简洁的Swift代码。这是我能想出的最严格的代码，可以用键盘上下移动文本视图。它目前正在iOS8/9 Swift 2生产应用程序中运行。

更新(2016年3月): 我只是尽可能地压缩了之前的代码。此外，这里还有一些流行的答案，它们硬编码了键盘高度和动画参数。这是没有必要的，更不用说这些答案中的数字并不总是与我在6s+ iOS9上看到的实际值一致(键盘高度226，持续时间0.25，动画曲线7)。在任何情况下，几乎不需要额外的代码来直接从系统获取这些值。见下文。

override func viewDidLoad() {
    super.viewDidLoad()

    NSNotificationCenter.defaultCenter().addObserver(self, selector: "animateWithKeyboard:", name: UIKeyboardWillShowNotification, object: nil)
    NSNotificationCenter.defaultCenter().addObserver(self, selector: "animateWithKeyboard:", name: UIKeyboardWillHideNotification, object: nil)
}

func animateWithKeyboard(notification: NSNotification) {

    // Based on both Apple's docs and personal experience, 
    // I assume userInfo and its documented keys are available.
    // If you'd like, you can remove the forced unwrapping and add your own default values.

    let userInfo = notification.userInfo!
    let keyboardHeight = (userInfo[UIKeyboardFrameEndUserInfoKey] as! NSValue).CGRectValue().height
    let duration = userInfo[UIKeyboardAnimationDurationUserInfoKey] as! Double
    let curve = userInfo[UIKeyboardAnimationCurveUserInfoKey] as! UInt
    let moveUp = (notification.name == UIKeyboardWillShowNotification)

    // baseContraint is your Auto Layout constraint that pins the
    // text view to the bottom of the superview.

    baseConstraint.constant = moveUp ? -keyboardHeight : 0

    let options = UIViewAnimationOptions(rawValue: curve << 16)
    UIView.animateWithDuration(duration, delay: 0, options: options,
        animations: {
            self.view.layoutIfNeeded()
        },
        completion: nil
    )

}

注意:这段代码涵盖了大多数注释/一般情况。然而，处理不同的方向和/或自定义键盘可能需要更多的代码。如果你需要处理每一个场景，这可能会有所帮助。

我使用的Swift 4解决方案需要键盘大小。将serverStatusStackView替换为任何你关心的视图，例如:self.view:

deinit {
    NotificationCenter.default.removeObserver(self)
}

@objc func keyboardWillShow(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
        serverStatusStackView.frame.origin.y = keyboardSize.height * 2 - serverStatusStackView.frame.height
    }
}

@objc func keyboardWillHide(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
        serverStatusStackView.frame.origin.y += keyboardSize.height
    }
}

override func viewDidLoad() {
    super.viewDidLoad()
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(notification:)), name: NSNotification.Name.UIKeyboardWillShow, object: nil)

    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(notification:)), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}