我使用Swift与iOS编程,我使用这段代码来移动UITextField,但它不起作用。我正确地调用了函数keyboardWillShow,但是文本字段没有移动。我正在使用自动布局。

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);
}

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

func keyboardWillShow(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue() {
        //let contentInsets = UIEdgeInsets(top: 0, left: 0, bottom: keyboardSize.height, right: 0)

        var frame = self.ChatField.frame
        frame.origin.y = frame.origin.y - keyboardSize.height + 167
        self.chatField.frame = frame
        println("asdasd")
    }
}

当前回答

最好的方法是使用NotificationCenter来捕捉键盘动作。您可以按照这篇短文中的步骤操作 https://medium.com/@demirciy/keyboard-handling-deb1a96a8207

其他回答

最好的方法是使用NotificationCenter来捕捉键盘动作。您可以按照这篇短文中的步骤操作 https://medium.com/@demirciy/keyboard-handling-deb1a96a8207

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
  }

我已采取以下方式:

当textfield superview为view时,这很有用

class AdminLoginViewController: UIViewController,
UITextFieldDelegate{

    @IBOutlet weak var txtUserName: UITextField!
    @IBOutlet weak var txtUserPassword: UITextField!
    @IBOutlet weak var btnAdminLogin: UIButton!

    private var activeField : UIView?

    var param:String!
    var adminUser : Admin? = nil
    var kbHeight: CGFloat!

    override func viewDidLoad()
    {
        self.addKeyBoardObserver()
        self.addGestureForHideKeyBoard()
    }

    override func viewWillDisappear(animated: Bool) {
        super.viewWillDisappear(animated)
    }
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }

    func addGestureForHideKeyBoard()
    {
        let tapGesture = UITapGestureRecognizer(target: self, action: Selector("hideKeyboard"))
        tapGesture.cancelsTouchesInView = false
        view.addGestureRecognizer(tapGesture)
    }

    func hideKeyboard() {
        self.view.endEditing(true)
    }

    func addKeyBoardObserver(){

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

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

    //MARK:- textfiled Delegate

    func textFieldShouldBeginEditing(textField: UITextField) -> Bool
    {
         activeField = textField

        return true
    }
    func textFieldShouldEndEditing(textField: UITextField) -> Bool
    {
        if activeField == textField
        {
            activeField = nil
        }

        return true
    }

    func textFieldShouldReturn(textField: UITextField) -> Bool {

        if txtUserName == textField
        {
            txtUserPassword.becomeFirstResponder()
        }
        else if (textField == txtUserPassword)
        {
            self.btnAdminLoginAction(nil)
        }
        return true;
    }

    func willChangeKeyboardFrame(aNotification : NSNotification)
    {
       if self.activeField != nil && self.activeField!.isFirstResponder()
    {
        if let keyboardSize =  (aNotification.userInfo![UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue()
        {
            let dy = (self.activeField?.superview?.convertRect((self.activeField?.frame)!, toView: view).origin.y)!

            let height = (self.view.frame.size.height - keyboardSize.size.height)

            if dy > height
            {
                var frame = self.view.frame

                frame.origin.y = -((dy - height) + (self.activeField?.frame.size.height)! + 20)

                self.view.frame = frame
            }
        }
    }
    else
    {
        var frame = self.view.frame
        frame.origin.y = 0
        self.view.frame = frame
    }
    } }

我创建了一个Swift 3协议来处理键盘的出现/消失

import UIKit

protocol KeyboardHandler: class {

var bottomConstraint: NSLayoutConstraint! { get set }

    func keyboardWillShow(_ notification: Notification)
    func keyboardWillHide(_ notification: Notification)
    func startObservingKeyboardChanges()
    func stopObservingKeyboardChanges()
}


extension KeyboardHandler where Self: UIViewController {

    func startObservingKeyboardChanges() {

        // NotificationCenter observers
        NotificationCenter.default.addObserver(forName: NSNotification.Name.UIKeyboardWillShow, object: nil, queue: nil) { [weak self] notification in
          self?.keyboardWillShow(notification)
        }

        // Deal with rotations
        NotificationCenter.default.addObserver(forName: NSNotification.Name.UIKeyboardWillChangeFrame, object: nil, queue: nil) { [weak self] notification in
          self?.keyboardWillShow(notification)
        }

        // Deal with keyboard change (emoji, numerical, etc.)
        NotificationCenter.default.addObserver(forName: NSNotification.Name.UITextInputCurrentInputModeDidChange, object: nil, queue: nil) { [weak self] notification in
          self?.keyboardWillShow(notification)
        }

        NotificationCenter.default.addObserver(forName: NSNotification.Name.UIKeyboardWillHide, object: nil, queue: nil) { [weak self] notification in
          self?.keyboardWillHide(notification)
        }
    }


    func keyboardWillShow(_ notification: Notification) {

      let verticalPadding: CGFloat = 20 // Padding between the bottom of the view and the top of the keyboard

      guard let value = notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue else { return }
      let keyboardHeight = value.cgRectValue.height

      // Here you could have more complex rules, like checking if the textField currently selected is actually covered by the keyboard, but that's out of this scope.
      self.bottomConstraint.constant = keyboardHeight + verticalPadding

      UIView.animate(withDuration: 0.1, animations: { () -> Void in
          self.view.layoutIfNeeded()
      })
  }


  func keyboardWillHide(_ notification: Notification) {
      self.bottomConstraint.constant = 0

      UIView.animate(withDuration: 0.1, animations: { () -> Void in
          self.view.layoutIfNeeded()
      })
  }


  func stopObservingKeyboardChanges() {
      NotificationCenter.default.removeObserver(self)
  }

}

然后,要在UIViewController中实现它,执行以下操作:

let the viewController conform to this protocol : class FormMailVC: UIViewControlle, KeyboardHandler { start observing keyboard changes in viewWillAppear: // MARK: - View controller life cycle override func viewWillAppear(_ animated: Bool) { super.viewWillAppear(animated) startObservingKeyboardChanges() } stop observing keyboard changes in viewWillDisappear: override func viewWillDisappear(_ animated: Bool) { super.viewWillDisappear(animated) stopObservingKeyboardChanges() } create an IBOutlet for the bottom constraint from the storyboard: // NSLayoutConstraints @IBOutlet weak var bottomConstraint: NSLayoutConstraint! (I recommend having all of your UI embedded inside a "contentView", and linking to this property the bottom constraint from this contentView to the bottom layout guide) change the constraint priority of the top constraint to 250 (low)

这是为了让整个内容视图在键盘出现时向上滑动。 优先级必须低于子视图中的任何其他约束优先级,包括内容拥抱优先级/内容抗压缩优先级。

确保你的自动布局有足够的约束来决定contentView应该如何滑动。

你可能需要添加一个“大于等于”的约束:

给你!

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