这是我的解决方案(实际上这段代码是在你的视图中有几个文本字段的情况下，这也适用于当你有一个文本字段的情况下)

class MyViewController: UIViewController, UITextFieldDelegate {

@IBOutlet weak var firstTextField: UITextField!
@IBOutlet weak var secondTextField: UITextField!

var activeTextField: UITextField!
var viewWasMoved: Bool = false


override func viewDidLoad() {
    super.viewDidLoad()
    NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(PrintViewController.keyboardWillShow(_:)), name: UIKeyboardWillShowNotification, object: nil)
    NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(PrintViewController.keyboardWillHide(_:)), name: UIKeyboardWillHideNotification, object: nil)
}

override func viewDidDisappear(animated: Bool) {
    super.viewWillDisappear(animated)
    NSNotificationCenter.defaultCenter().removeObserver(self)
}

func textFieldDidBeginEditing(textField: UITextField) {
    self.activeTextField = textField
}

func textFieldDidEndEditing(textField: UITextField) {
    self.activeTextField = nil
}

func textFieldShouldReturn(textField: UITextField) -> Bool {
    textField.resignFirstResponder()
    return true
}


func keyboardWillShow(notification: NSNotification) {

    let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue()

    var aRect: CGRect = self.view.frame
    aRect.size.height -= keyboardSize!.height

    let activeTextFieldRect: CGRect? = activeTextField?.frame
    let activeTextFieldOrigin: CGPoint? = activeTextFieldRect?.origin

    if (!CGRectContainsPoint(aRect, activeTextFieldOrigin!)) {
        self.viewWasMoved = true
        self.view.frame.origin.y -= keyboardSize!.height
    } else {
        self.viewWasMoved = false
    }
}

func keyboardWillHide(notification: NSNotification) {
    if (self.viewWasMoved) {
        if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
            self.view.frame.origin.y += keyboardSize.height
        }
    }
}

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
    }
}

将这个添加到你的视图控制器中。效果非常好。只是调整数值。

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

@objc func keyboardWillShow(sender: NSNotification) {
    self.view.frame.origin.y -= 150
}
@objc func keyboardWillHide(sender: NSNotification) {
    self.view.frame.origin.y += 150
}

Swift 3代码

var activeField: UITextField?

override func viewDidLoad() {
    super.viewDidLoad()

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

func textFieldDidBeginEditing(_ textField: UITextField){
    activeField = textField
}

func textFieldDidEndEditing(_ textField: UITextField){
    activeField = nil
}

func keyboardWillShow(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
        if (self.activeField?.frame.origin.y)! >= keyboardSize.height {
            self.view.frame.origin.y = keyboardSize.height - (self.activeField?.frame.origin.y)!
        } else {
            self.view.frame.origin.y = 0
        }
    }
}

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

如果你在同一个VC中有2个或更多的文本字段，用户点击其中一个，然后点击另一个，不调用keyboardWillHide函数，视图会再向上一次，这是不必要的，因为你会有键盘，一个空格，它有键盘的高度，然后视图，使用我编辑的答案中的代码:

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)
}

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

func keyboardWillHide(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
        self.view.frame.origin.y += keyboardSize.height
    }
}

为了解决这个问题，将两个函数"KeyboardWillShow/Hide"替换为:

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

func keyboardWillHide(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
        if view.frame.origin.y != 0 {
            self.view.frame.origin.y += keyboardSize.height
        }
    }
}

func keyboardWillShow(notification: NSNotification) {

    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
        self.view.frame.origin.y = self.view.frame.height - (self.view.frame.height + keyboardSize.height)
    }

}

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

它必须更加稳定