由于在Combine中没有如何做到这一点的答案，这里是我使用的方法。

我们创建一个发布者来监听通知，显示和隐藏。 为了显示，我们从通知userInfo中获取键盘帧，并检查当前活动响应器是否包含在其中。如果被覆盖，返回键盘帧高度。如果它没有被覆盖，返回0，我们不想移动帧。对于隐藏通知，我们简单地返回0。

private var keyboardHeightPublisher: AnyPublisher<CGFloat, Never> {
    Publishers.Merge(
        NotificationCenter.default
            .publisher(for: UIResponder.keyboardWillShowNotification)
            .compactMap { $0.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? CGRect }
            .map { $0.intersects(self.view.firstResponder!.frame) ? $0.height : 0 }
            .map { $0 * -1 },
        NotificationCenter.default
            .publisher(for: UIResponder.keyboardWillHideNotification)
            .map { _ in CGFloat(0) }
    ).eraseToAnyPublisher()
}

在viewDidLoad中，我们只需订阅发布者，相应地改变视图框架。

override func viewDidLoad() {
    super.viewDidLoad()

    keyboardHeightPublisher.sink{ [weak self] height in
        self?.view.frame.origin.y = height
    }.store(in: &cancelables)
}

编辑 小心!如果firstResponder在子视图中，你必须计算与整个屏幕相对应的帧，以检查它们是否相交。 例子:

let myViewGlobalFrame = myView.convert(myView.frame, to: parentView)

当打开键盘时，它100%完美地回答了所有人的更新表视图高度

对于Swift4.2

   override func viewDidLoad() {
      super.viewDidLoad()
      NotificationCenter.default.addObserver(self, selector: #selector(RecipeVC.keyboardWillShow), name: UIResponder.keyboardWillShowNotification, object: nil)

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

   @objc func keyboardWillShow(notification: NSNotification) {
    if ((notification.userInfo?[UIResponder.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue) != nil {

        var userInfo = notification.userInfo!
        var keyboardFrame:CGRect = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as! NSValue).cgRectValue
        keyboardFrame = self.view.convert(keyboardFrame, from: nil)

        var contentInset:UIEdgeInsets = self.tbl.contentInset
          contentInset.bottom = keyboardFrame.size.height
          self.tbl.contentInset = contentInset
    }
}

   @objc func keyboardWillHide(notification: NSNotification) {
    if ((notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue) != nil {
        let contentInset:UIEdgeInsets = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)
        self.tbl.contentInset = contentInset
    }
}

Swift3.2

    override func viewDidLoad() {
          super.viewDidLoad()

           NotificationCenter.default.addObserver(self, selector: #selector(RecipeVC.keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)

           NotificationCenter.default.addObserver(self, selector: #selector(RecipeVC.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
    }
    func keyboardWillShow(notification: NSNotification) {
         if ((notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue) != nil {
         //self.view.frame.origin.y -= keyboardSize.height
         var userInfo = notification.userInfo!
         var keyboardFrame:CGRect = (userInfo[UIKeyboardFrameEndUserInfoKey] as! NSValue).cgRectValue
          keyboardFrame = self.view.convert(keyboardFrame, from: nil)

          var contentInset:UIEdgeInsets = self.tbl.contentInset
          contentInset.bottom = keyboardFrame.size.height
          self.tbl.contentInset = contentInset

       }
    }

    func keyboardWillHide(notification: NSNotification) {
         if ((notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue) != nil {
         let contentInset:UIEdgeInsets = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)
         self.tbl.contentInset = contentInset
         }
    }

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

对于黑屏错误(Swift 4和4.2)。

我解决了黑屏的问题。在验证方案中，敲击后键盘高度变化，导致黑屏。

必须使用UIKeyboardFrameEndUserInfoKey而不是UIKeyboardFrameBeginUserInfoKey

var isKeyboardAppear = false

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

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

我做了一个椰子荚来简化问题:

https://github.com/xtrinch/KeyboardLayoutHelper

如何使用:

做一个自动布局底部约束，在模块KeyboardLayoutHelper中给它一个KeyboardLayoutConstraint类，pod将做必要的工作来增加它，以适应出现和消失的键盘。关于如何使用它(我做了两个:一个scrollView内的textFields，和垂直居中的textFields与两个基本视图-登录和注册)的例子项目。

底部布局约束可以是容器视图，textField本身，任何你能想到的。

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
  }
}