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

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

 }

 // MARK: - keyboard
 func keyboardWillShow(notification: NSNotification) 
{

if let userInfo = notification.userInfo {
if let keyboardSize = (userInfo[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
let contentInsets = self.tblView.contentInset as UIEdgeInsets
self.tblView.contentInset = UIEdgeInsets(top: contentInsets.top, left: contentInsets.left, bottom: keyboardSize.height, right:contentInsets.right)
                    // ...
                } else {
                    // no UIKeyboardFrameBeginUserInfoKey entry in userInfo
                }
            } else {
                // no userInfo dictionary in notification
            }
        }

func keyboardWillHide(notification: NSNotification) 
{
let contentInsets = self.tblView.contentInset as UIEdgeInsets
self.tblView.contentInset = UIEdgeInsets(top: contentInsets.top, left: contentInsets.left, bottom: 0, right:contentInsets.right)
 }

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

我看到所有的答案都是通过键盘高度的值移动视图本身。好吧，我有一个详细的答案，这可能是有用的，如果你正在使用约束即自动布局，移动一个视图通过改变其约束值(底部或顶部约束为例)由一个预定义的值或你可以使用键盘大小值。

在这个例子中，我使用底部约束从文本字段到底部布局视图的初始值为175。

@IBOutlet weak var bottomConstraint: NSLayoutConstraint!

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) {
    //To retrieve keyboard size, uncomment following line
    //let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue()
    bottomConstraint.constant = 260
    UIView.animateWithDuration(0.3) {
        self.view.layoutIfNeeded()
    }
}

func keyboardWillHide(notification: NSNotification) {
    //To retrieve keyboard size, uncomment following line
    //let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue()
    bottomConstraint.constant = 175
    UIView.animateWithDuration(0.3) {
        self.view.layoutIfNeeded()
    }
}

如果你像我一样尝试了以上所有的解决方案，但你的问题仍然没有解决，我有一个很棒的解决方案，它就像一个魅力。首先我想澄清一下上面提到的一些解决方案。

In my case IQkeyboardmanager was working only when there is no auto layout applied on the elements, if it is applied then IQkeyboard manager will not work the way we think. Same thing with upward movement of self.view. i have wriiten a objective c header with a swift support for pushing UITexfield upward when user clicks on it, solving the problem of keyboard covering the UITextfield : https://github.com/coolvasanth/smart_keyboard. One who has An intermediate or higher level in iOS app development can easily understand the repository and implement it. All the best

这个实现(Swift 4)将给你的行为最接近Android的默认行为。Ie:当活动文本域在键盘下时，将视图向上移动，当用户切换到另一个视图时，无需关闭键盘。记住调用settextfielddelegate()。

public class DelegateProxy: NSObject, UITextFieldDelegate {

  private static let instance = DelegateProxies()

  weak var activeTextField: UITextField?
  var offset: CGFloat = 0
  weak var vc: UIViewController?
  var keyboardHeight: CGFloat = 0

  public static func getDelegate(root: UIViewController) -> DelegateProxies {
    instance.vc = root
    return instance
  }

  public static func getDelegate() -> DelegateProxies {
    return instance
  }

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


  public func textFieldShouldBeginEditing(_ textField: UITextField) -> Bool {

    self.activeTextField = textField

    let globalPointY: CGFloat = (textField.superview?.convert(textField.frame.origin, to: nil).y ?? CGFloat(0)) + textField.frame.height


    offset = UIScreen.main.bounds.height - globalPointY

    if keyboardHeight > 0 {
        vc?.moveViewUp(offsetFromKeyboard: keyboardHeight - offset)
    }

    return true
  }
}


extension UIViewController {

  private func setTextFieldDelegates(parentView: UIView) {
    for child in parentView.subviews {
        setTextFieldDelegates(parentView: child)
        (child as? UITextField)?.delegate = DelegateProxies.getDelegate(root: self)
    }
  }

  func registerAutoResizeOnKeyboardAppear(){
    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)
  }

  func unregisterAutoResizeOnKeyboard(){
    NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillShow, object: nil)
    NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillHide, object: nil)
  }

  @objc func keyboardWillShow(notification: NSNotification) {

    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
        let offsetFromKeyboard = keyboardSize.height - DelegateProxies.getDelegate().offset
        DelegateProxies.getDelegate().keyboardHeight = keyboardSize.height

        moveViewUp(offsetFromKeyboard: offsetFromKeyboard)
    }
  }

  func moveViewUp(offsetFromKeyboard: CGFloat){
    print("offset from keyboard: \(offsetFromKeyboard)")

    let moveOffset = offsetFromKeyboard + 8

    if offsetFromKeyboard > 0 {
        self.view.frame.origin.y = -moveOffset
    }

    if offsetFromKeyboard < 0 && view.frame.origin.y < 0 {
        self.view.frame.origin.y += -moveOffset
        if self.view.frame.origin.y > 0{
            self.view.frame.origin.y = 0
        }
    }
  }

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

这是一个解决方案，不处理从一个textField到另一个切换:

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?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.CGRectValue() {
        self.view.frame.origin.y -= keyboardSize.height
    }            
}

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

要解决这个问题，将keyboardWillShow/Hide替换为以下两个函数:

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

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

斯威夫特3.0:

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

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

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

斯威夫特4.0:

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

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

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

斯威夫特4.2:

override func viewDidLoad() {
    super.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)
}

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

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