管理键盘的完整代码。

        override func viewWillAppear(_ animated: Bool) {
            NotificationCenter.default.addObserver(self, selector: #selector(StoryMediaVC.keyboardWillShow), name: UIResponder.keyboardWillShowNotification, object: nil)
            NotificationCenter.default.addObserver(self, selector: #selector(StoryMediaVC.keyboardWillHide), name: UIResponder.keyboardWillHideNotification, object: nil)
        }
        override func viewWillDisappear(_ animated: Bool) {
            NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillShowNotification, object: nil)
            NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillHideNotification, object: nil)
        }
        @objc func keyboardWillShow(notification: NSNotification) {
            guard let userInfo = notification.userInfo else {return}
            guard let keyboardSize = userInfo[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue else {return}
            let keyboardFrame = keyboardSize.cgRectValue

            if self.view.bounds.origin.y == 0{
                self.view.bounds.origin.y += keyboardFrame.height
            }
        }


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

我修改了一点@Simpa解决方案.........

override func viewDidLoad() 
{

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

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

var keyboardIsVisible = false
override 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 && keyboardIsVisible == false{

        keyboardIsVisible = true

        UIView.animateWithDuration(duration, animations: { () -> Void in
            var frame = self.view.frame
            frame.size.height = frame.size.height - keyboardHeight
            self.view.frame = frame
        })

    } else if keyboardIsVisible == true && notification.name == UIKeyboardWillShowNotification{

    }else {
        keyboardIsVisible = false

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

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);

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。

对于任何不使用故事板设置布局约束的人。这是一种纯粹的编程方式，让它在Swift 5上工作:

在viewController中定义一个空约束。在这种情况下，我正在构建一个聊天应用程序，在屏幕的最底部有一个包含文本视图的UIView。

var discussionsMessageBoxBottomAnchor: NSLayoutConstraint = NSLayoutConstraint()

在viewDidLoad中为最底部的视图添加约束。在本例中是discussionsMessageBox。另外，为键盘事件添加监听器。

为了正确地初始化约束，您需要首先添加子视图，然后定义约束。

NotificationCenter.default.addObserver(self,
                                       selector: #selector(self.keyboardNotification(notification:)),
                                       name: NSNotification.Name.UIKeyboardWillChangeFrame,
                                       object: nil)

view.addSubview(discussionsMessageBox)

if #available(iOS 11.0, *) {
    discussionsMessageBoxBottomAnchor = discussionsMessageBox.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor, constant: 0)
} else {
    // Fallback on earlier versions
    discussionsMessageBoxBottomAnchor = discussionsMessageBox.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: 0)
}

NSLayoutConstraint.activate([ discussionsMessageBoxBottomAnchor ])

定义deinit。

deinit {
        NotificationCenter.default.removeObserver(self)
    }

接下来添加@JosephLord定义的代码，并对偏移量进行修正。

extension DiscussionsViewController {
    @objc func keyboardNotification(notification: NSNotification) {
        guard let userInfo = notification.userInfo else { return }
        
        let endFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue
        let endFrameY = endFrame?.origin.y ?? 0
        let duration:TimeInterval = (userInfo[UIKeyboardAnimationDurationUserInfoKey] as? NSNumber)?.doubleValue ?? 0
        let animationCurveRawNSN = userInfo[UIKeyboardAnimationCurveUserInfoKey] as? NSNumber
        let animationCurveRaw = animationCurveRawNSN?.uintValue ?? UIView.AnimationOptions.curveEaseInOut.rawValue
        let animationCurve:UIView.AnimationOptions = UIView.AnimationOptions(rawValue: animationCurveRaw)
        
        if endFrameY >= UIScreen.main.bounds.size.height {
            self.discussionsMessageBoxBottomAnchor.constant = 0.0
        } else {
            //Changed line
            self.discussionsMessageBoxBottomAnchor.constant = -1 * (endFrame?.size.height ?? 0.0)
        }
        
        UIView.animate(
            withDuration: duration,
            delay: TimeInterval(0),
            options: animationCurve,
            animations: { self.view.layoutIfNeeded() },
            completion: nil)
    }
}

Well, I think i might be too late but i found another simple version of Saqib's answer. I'm using Autolayout with constraints. I have a small view inside of another main view with username and password fields. Instead of changing the y coordinate of the view i'm saving the original constraint value in a variable and changing the constraint's constant to some value and again after the keyboard dismisses, i'm setting up the constraint to original one. This way it avoids the problem Saqib's answer has, (The view keeps on moving up and does not stop). Below is my code...

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);
    self.originalConstraint = self.centerYConstraint.constant
  }

  func keyboardWillShow(sender: NSNotification) {
    self.centerYConstraint.constant += 30
  }

  func keyboardWillHide(sender: NSNotification) {
    self.centerYConstraint.constant = self.originalConstraint
  }