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
        })
    }

}

我的做法如下:

class SignInController: UIViewController , UITextFieldDelegate {

@IBOutlet weak var scrollView: UIScrollView!

// outlet declartion
@IBOutlet weak var signInTextView: UITextField!

var kbHeight: CGFloat!

/**
*
* @method viewDidLoad
*
*/

override func viewDidLoad() {
    super.viewDidLoad()

    self.signInTextView.delegate = self

}// end viewDidLoad

/**
*
* @method viewWillAppear
*
*/

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

    NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillShow:"), name: UIKeyboardWillShowNotification, object: nil)

    NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillHide:"), name: UIKeyboardWillHideNotification, object: nil)

}// end viewWillAppear

/**
*
* @method viewDidAppear
*
*/

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


}// end viewDidAppear

/**
*
* @method viewWillDisappear
*
*/
override func viewWillDisappear(animated: Bool) {
    super.viewWillDisappear(animated)
    NSNotificationCenter.defaultCenter().removeObserver(self)
}

/**
*
* @method textFieldShouldReturn
* retun the keyboard value
*
*/

// MARK -
func textFieldShouldReturn(textField: UITextField) -> Bool {
    signInTextView.resignFirstResponder()
    return true;

}// end textFieldShouldReturn

// MARK - keyboardWillShow
func keyboardWillShow(notification: NSNotification) {
    if let userInfo = notification.userInfo {
        if let keyboardSize =  (userInfo[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
            kbHeight = keyboardSize.height
            self.animateTextField(true)
        }
    }
}// end keyboardWillShow

// MARK - keyboardWillHide
func keyboardWillHide(notification: NSNotification) {
    self.animateTextField(false)
}// end keyboardWillHide

// MARK - animateTextField
func animateTextField(up: Bool) {
    var movement = (up ? -kbHeight : kbHeight)

    UIView.animateWithDuration(0.3, animations: {
        self.view.frame = CGRectOffset(self.view.frame, 0, movement)
    })
}// end animateTextField

/**
*
* @method didReceiveMemoryWarning
*
*/

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.

}// end didReceiveMemoryWarning


}// end SignInController

下面是一个简单的解决方案，其中文本字段有一个约束将其绑定到底部布局指南。它只是将键盘高度添加到约束常数中。

// This constraint ties the text field to the bottom layout guide
@IBOutlet var textFieldToBottomLayoutGuideConstraint: NSLayoutConstraint!

override func viewDidLoad() {
    super.viewDidLoad()

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

func keyboardWillShow(sender: NSNotification) {
    if let keyboardSize = (sender.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
        self.textFieldToBottomLayoutGuideConstraint?.constant += keyboardSize.height
    }
}

func keyboardWillHide(sender: NSNotification) {
    if let keyboardSize = (sender.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
        self.textFieldToBottomLayoutGuideConstraint?.constant -= keyboardSize.height
    }
}

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)

    }

如果你正在使用自动布局，我假设你已经设置了底部空间为Superview约束。如果是这种情况，您只需更新约束的值。这是你如何用一点动画来做到这一点。

func keyboardWasShown(notification: NSNotification) {
    let info = notification.userInfo!
    let keyboardFrame: CGRect = (info[UIKeyboardFrameEndUserInfoKey] as! NSValue).CGRectValue()

    UIView.animateWithDuration(0.1, animations: { () -> Void in
        self.bottomConstraint.constant = keyboardFrame.size.height + 20
    })
}

添加硬编码的20只是为了将文本框弹出到键盘上方一点。否则键盘的上边距和文本框的下边距将会接触。

当键盘关闭时，将约束的值重置为原始值。