这是一个改进版的@JosephLord和@Hlung的回答。 无论你是否有标签栏，它都适用。 并且它可以完美地恢复由键盘移动到原始位置的视图。

// You have to set this up in storyboard first!. 
// It's a vertical spacing constraint between view and bottom of superview.
@IBOutlet weak var bottomSpacingConstraint: NSLayoutConstraint! 

override func viewDidLoad() {
        super.viewDidLoad()            

        //    Receive(Get) Notification
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardNotification:", name: UIKeyboardWillShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardNotification:", name: UIKeyboardWillHideNotification, object: nil)


        self.originalConstraint = self.keyboardHeightLayoutConstraint?.constant //for original coordinate.
}

func keyboardNotification(notification: NSNotification) {
        let isShowing = notification.name == UIKeyboardWillShowNotification

        var tabbarHeight: CGFloat = 0
        if self.tabBarController? != nil {
            tabbarHeight = self.tabBarController!.tabBar.frame.height
        }
        if let userInfo = notification.userInfo {
            let endFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.CGRectValue()
            let duration:NSTimeInterval = (userInfo[UIKeyboardAnimationDurationUserInfoKey] as? NSNumber)?.doubleValue ?? 0
            let animationCurveRawNSN = userInfo[UIKeyboardAnimationCurveUserInfoKey] as? NSNumber
            let animationCurveRaw = animationCurveRawNSN?.unsignedLongValue ?? UIViewAnimationOptions.CurveEaseInOut.rawValue
            let animationCurve:UIViewAnimationOptions = UIViewAnimationOptions(rawValue: animationCurveRaw)
            self.keyboardHeightLayoutConstraint?.constant = isShowing ? (endFrame!.size.height - tabbarHeight) : self.originalConstraint!
            UIView.animateWithDuration(duration,
                delay: NSTimeInterval(0),
                options: animationCurve,
                animations: { self.view.layoutIfNeeded() },
                completion: nil)
        }
}

最简单的不需要任何代码的方法:

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，为对象/视图/文本字段创建一个底部约束，选择约束(双击它)并在标识检查器中，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。

可以使用这样简单的UIViewController扩展

//MARK: - Observers
extension UIViewController {

    func addObserverForNotification(notificationName: String, actionBlock: (NSNotification) -> Void) {
        NSNotificationCenter.defaultCenter().addObserverForName(notificationName, object: nil, queue: NSOperationQueue.mainQueue(), usingBlock: actionBlock)
    }

    func removeObserver(observer: AnyObject, notificationName: String) {
        NSNotificationCenter.defaultCenter().removeObserver(observer, name: notificationName, object: nil)
    }
}

//MARK: - Keyboard observers
extension UIViewController {

    typealias KeyboardHeightClosure = (CGFloat) -> ()

    func addKeyboardChangeFrameObserver(willShow willShowClosure: KeyboardHeightClosure?,
        willHide willHideClosure: KeyboardHeightClosure?) {
            NSNotificationCenter.defaultCenter().addObserverForName(UIKeyboardWillChangeFrameNotification,
                object: nil, queue: NSOperationQueue.mainQueue(), usingBlock: { [weak self](notification) in
                    if let userInfo = notification.userInfo,
                        let frame = (userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.CGRectValue(),
                        let duration = userInfo[UIKeyboardAnimationDurationUserInfoKey] as? Double,
                        let c = userInfo[UIKeyboardAnimationCurveUserInfoKey] as? UInt,
                        let kFrame = self?.view.convertRect(frame, fromView: nil),
                        let kBounds = self?.view.bounds {

                            let animationType = UIViewAnimationOptions(rawValue: c)
                            let kHeight = kFrame.size.height
                            UIView.animateWithDuration(duration, delay: 0, options: animationType, animations: {
                                if CGRectIntersectsRect(kBounds, kFrame) { // keyboard will be shown
                                    willShowClosure?(kHeight)
                                } else { // keyboard will be hidden
                                    willHideClosure?(kHeight)
                                }
                                }, completion: nil)
                    } else {
                            print("Invalid conditions for UIKeyboardWillChangeFrameNotification")
                    }
            })
    }

    func removeKeyboardObserver() {
        removeObserver(self, notificationName: UIKeyboardWillChangeFrameNotification)
    }
}

用法示例

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

        removeKeyboardObserver()
    }

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

    addKeyboardChangeFrameObserver(willShow: { [weak self](height) in
        //Update constraints here
        self?.view.setNeedsUpdateConstraints()
        }, willHide: { [weak self](height) in
        //Reset constraints here
        self?.view.setNeedsUpdateConstraints()
    })
}

Swift 4解决方案

//MARK: - Observers
extension UIViewController {

  func addObserverForNotification(_ notificationName: Notification.Name, actionBlock: @escaping (Notification) -> Void) {
    NotificationCenter.default.addObserver(forName: notificationName, object: nil, queue: OperationQueue.main, using: actionBlock)
  }

  func removeObserver(_ observer: AnyObject, notificationName: Notification.Name) {
    NotificationCenter.default.removeObserver(observer, name: notificationName, object: nil)
  }
}

//MARK: - Keyboard handling
extension UIViewController {

  typealias KeyboardHeightClosure = (CGFloat) -> ()

  func addKeyboardChangeFrameObserver(willShow willShowClosure: KeyboardHeightClosure?,
                                      willHide willHideClosure: KeyboardHeightClosure?) {
    NotificationCenter.default.addObserver(forName: NSNotification.Name.UIKeyboardWillChangeFrame,
                                           object: nil, queue: OperationQueue.main, using: { [weak self](notification) in
                                            if let userInfo = notification.userInfo,
                                              let frame = (userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue,
                                              let duration = userInfo[UIKeyboardAnimationDurationUserInfoKey] as? Double,
                                              let c = userInfo[UIKeyboardAnimationCurveUserInfoKey] as? UInt,
                                              let kFrame = self?.view.convert(frame, from: nil),
                                              let kBounds = self?.view.bounds {

                                              let animationType = UIViewAnimationOptions(rawValue: c)
                                              let kHeight = kFrame.size.height
                                              UIView.animate(withDuration: duration, delay: 0, options: animationType, animations: {
                                                if kBounds.intersects(kFrame) { // keyboard will be shown
                                                  willShowClosure?(kHeight)
                                                } else { // keyboard will be hidden
                                                  willHideClosure?(kHeight)
                                                }
                                              }, completion: nil)
                                            } else {
                                              print("Invalid conditions for UIKeyboardWillChangeFrameNotification")
                                            }
    })
  }

  func removeKeyboardObserver() {
    removeObserver(self, notificationName: NSNotification.Name.UIKeyboardWillChangeFrame)
  }
}

斯威夫特4.2

//MARK: - Keyboard handling
extension UIViewController {

    func addObserverForNotification(_ notificationName: Notification.Name, actionBlock: @escaping (Notification) -> Void) {
        NotificationCenter.default.addObserver(forName: notificationName, object: nil, queue: OperationQueue.main, using: actionBlock)
    }

    func removeObserver(_ observer: AnyObject, notificationName: Notification.Name) {
        NotificationCenter.default.removeObserver(observer, name: notificationName, object: nil)
    }

    typealias KeyboardHeightClosure = (CGFloat) -> ()

    func removeKeyboardObserver() {
        removeObserver(self, notificationName: UIResponder.keyboardWillChangeFrameNotification)
    }

    func addKeyboardChangeFrameObserver(willShow willShowClosure: KeyboardHeightClosure?,
                                        willHide willHideClosure: KeyboardHeightClosure?) {
        NotificationCenter.default.addObserver(forName: UIResponder.keyboardWillChangeFrameNotification,
                                               object: nil, queue: OperationQueue.main, using: { [weak self](notification) in
                                                if let userInfo = notification.userInfo,
                                                    let frame = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue,
                                                    let duration = userInfo[UIResponder.keyboardAnimationDurationUserInfoKey] as? Double,
                                                    let c = userInfo[UIResponder.keyboardAnimationCurveUserInfoKey] as? UInt,
                                                    let kFrame = self?.view.convert(frame, from: nil),
                                                    let kBounds = self?.view.bounds {

                                                    let animationType = UIView.AnimationOptions(rawValue: c)
                                                    let kHeight = kFrame.size.height
                                                    UIView.animate(withDuration: duration, delay: 0, options: animationType, animations: {
                                                        if kBounds.intersects(kFrame) { // keyboard will be shown
                                                            willShowClosure?(kHeight)
                                                        } else { // keyboard will be hidden
                                                            willHideClosure?(kHeight)
                                                        }
                                                    }, completion: nil)
                                                } else {
                                                    print("Invalid conditions for UIKeyboardWillChangeFrameNotification")
                                                }
        })
    }
}

一个简单的解决方案是移动视图与键盘高度常数。

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);
}

@objc func keyboardWillShow(sender: NSNotification) {
     self.view.frame.origin.y = -150 // Move view 150 points upward 
}

@objc func keyboardWillHide(sender: NSNotification) {
     self.view.frame.origin.y = 0 // Move view to original position  
}

斯威夫特5:

NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(sender:)), name: UIResponder.keyboardWillShowNotification, object: nil);

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

我正在使用swift 4，我解决了这个问题，没有使用任何额外的底部约束，看我的代码在这里。这对我的案子很有帮助

1)在did load中添加通知观察者

override func viewDidLoad() { super.viewDidLoad () setupManager () //加载视图后进行任何额外的设置。 addobserver (self, selector: #selector(self. keyboardwillshow)， name: NSNotification.Name。对象:nil) addobserver (self, selector: #selector(self. keyboardwillhide)， name: NSNotification.Name。对象:nil) ｝

2)删除通知观察者

Deinit { NotificationCenter.default.removeObserver（self） }

3)增加键盘显示/隐藏方法

 @objc func keyboardWillShow(notification: NSNotification) {
            if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
                UIView.animate(withDuration: 0.1, animations: { () -> Void in
                    self.view.frame.origin.y -= keyboardSize.height
                    self.view.layoutIfNeeded()
                })
            }
        }

@objc func keyboardWillHide(notification: NSNotification) {
        if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
            UIView.animate(withDuration: 0.1, animations: { () -> Void in
                self.view.frame.origin.y += keyboardSize.height
                self.view.layoutIfNeeded()
            })
        }
    }

4)添加textfield delegate和touchesBegan方法。usefull用于在屏幕上的textfield外触摸时隐藏键盘

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        view.endEditing(true)

    }

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。