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

我使用的Swift 4解决方案需要键盘大小。将serverStatusStackView替换为任何你关心的视图,例如:self.view:

deinit {
    NotificationCenter.default.removeObserver(self)
}

@objc func keyboardWillShow(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
        serverStatusStackView.frame.origin.y = keyboardSize.height * 2 - serverStatusStackView.frame.height
    }
}

@objc func keyboardWillHide(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
        serverStatusStackView.frame.origin.y += keyboardSize.height
    }
}

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

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

其他回答

    func registerForKeyboardNotifications(){
        //Keyboard
        NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(keyboardWasShown), name: UIKeyboardDidShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(keyboardWillBeHidden), name: UIKeyboardDidHideNotification, object: nil)


    }
    func deregisterFromKeyboardNotifications(){

        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillHideNotification, object: nil)

    }
    func keyboardWasShown(notification: NSNotification){

        let userInfo: NSDictionary = notification.userInfo!
        let keyboardInfoFrame = userInfo.objectForKey(UIKeyboardFrameEndUserInfoKey)?.CGRectValue()

        let windowFrame:CGRect = (UIApplication.sharedApplication().keyWindow!.convertRect(self.view.frame, fromView:self.view))

        let keyboardFrame = CGRectIntersection(windowFrame, keyboardInfoFrame!)

        let coveredFrame = UIApplication.sharedApplication().keyWindow!.convertRect(keyboardFrame, toView:self.view)

        let contentInsets = UIEdgeInsetsMake(0, 0, (coveredFrame.size.height), 0.0)
        self.scrollViewInAddCase .contentInset = contentInsets;
        self.scrollViewInAddCase.scrollIndicatorInsets = contentInsets;
        self.scrollViewInAddCase.contentSize = CGSizeMake((self.scrollViewInAddCase.contentSize.width), (self.scrollViewInAddCase.contentSize.height))

    }
    /**
     this method will fire when keyboard was hidden

     - parameter notification: contains keyboard details
     */
    func keyboardWillBeHidden (notification: NSNotification) {

        self.scrollViewInAddCase.contentInset = UIEdgeInsetsZero
        self.scrollViewInAddCase.scrollIndicatorInsets = UIEdgeInsetsZero

    }

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
    }
}

斯威夫特4。x答案,合并来自@Joseph Lord和@Isuru的答案。bottomConstraint表示你想移动的视图的底部约束。

override func viewDidLoad() {
    // Call super
    super.viewDidLoad()

    // Subscribe to keyboard notifications
    NotificationCenter.default.addObserver(self,
                                           selector: #selector(keyboardNotification(notification:)),
                                           name: UIResponder.keyboardWillChangeFrameNotification,
                                           object: nil)        
}


deinit {
    NotificationCenter.default.removeObserver(self)
}


@objc func keyboardNotification(notification: NSNotification) {
    if let userInfo = notification.userInfo {
        // Get keyboard frame
        let keyboardFrame = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as! NSValue).cgRectValue

        // Set new bottom constraint constant
        let bottomConstraintConstant = keyboardFrame.origin.y >= UIScreen.main.bounds.size.height ? 0.0 : keyboardFrame.size.height

        // Set animation properties
        let duration = (userInfo[UIResponder.keyboardAnimationDurationUserInfoKey] as? NSNumber)?.doubleValue ?? 0
        let animationCurveRawNSN = userInfo[UIResponder.keyboardAnimationCurveUserInfoKey] as? NSNumber
        let animationCurveRaw = animationCurveRawNSN?.uintValue ?? UIView.AnimationOptions.curveEaseInOut.rawValue
        let animationCurve = UIView.AnimationOptions(rawValue: animationCurveRaw)

        // Animate the view you care about
        UIView.animate(withDuration: duration, delay: 0, options: animationCurve, animations: {
            self.bottomConstraint.constant = bottomConstraintConstant
            self.view.layoutIfNeeded()
        }, completion: nil)
    }
}

如果视图上有多个文本字段,那么我建议您查看这个方法。当在字段之间切换时,你不会有视图跑开的问题,它会简单地适应所需的文本字段。它在swift 5中工作

  override func viewDidLoad() {
    super.viewDidLoad()
    registerForKeyboardNotification()
}

扩展中的所有方法

extension StartViewController: UITextFieldDelegate {

func registerForKeyboardNotification() {
    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) 
}

@objc func keyboardWillShow(sender: NSNotification) {
    guard let userInfo = sender.userInfo,
          let keyboardFrame = userInfo[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue,
          let currentTextField = UIResponder.currentFirst() as? UITextField  else { return }
         
    let keyboardTopY = keyboardFrame.cgRectValue.origin.y
    let convertedTextFieldFrame = view.convert(currentTextField.frame, from: currentTextField.superview)
    let textFieldBottomY = convertedTextFieldFrame.origin.y + convertedTextFieldFrame.size.height
    
    if textFieldBottomY > keyboardTopY {
        let textBoxY = convertedTextFieldFrame.origin.y
        let newFrameY = (textBoxY - keyboardTopY / 2) * -1
        view.frame.origin.y = newFrameY
    }
}


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


func textFieldShouldReturn(_ textField: UITextField) -> Bool {
    switch textField {
    case emailTextField :
        passwordTextField.becomeFirstResponder()
    default:
        emailTextField.becomeFirstResponder()  
    }
    return true
}

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    super.touchesBegan(touches , with:event)
    view.endEditing(true)
}
}

最后我们用UIResponder建立方法

extension UIResponder {
private struct Static {
    static weak var responder: UIResponder?
}

static func currentFirst() -> UIResponder? {
    Static.responder = nil
    UIApplication.shared.sendAction(#selector(UIResponder._trap), to: nil, from: nil, for: nil)
    return Static.responder
}

@objc private func _trap() {
    Static.responder = self
}
}

我喜欢简洁的Swift代码。这是我能想出的最严格的代码,可以用键盘上下移动文本视图。它目前正在iOS8/9 Swift 2生产应用程序中运行。

更新(2016年3月): 我只是尽可能地压缩了之前的代码。此外,这里还有一些流行的答案,它们硬编码了键盘高度和动画参数。这是没有必要的,更不用说这些答案中的数字并不总是与我在6s+ iOS9上看到的实际值一致(键盘高度226,持续时间0.25,动画曲线7)。在任何情况下,几乎不需要额外的代码来直接从系统获取这些值。见下文。

override func viewDidLoad() {
    super.viewDidLoad()

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

func animateWithKeyboard(notification: NSNotification) {

    // Based on both Apple's docs and personal experience, 
    // I assume userInfo and its documented keys are available.
    // If you'd like, you can remove the forced unwrapping and add your own default values.

    let userInfo = notification.userInfo!
    let keyboardHeight = (userInfo[UIKeyboardFrameEndUserInfoKey] as! NSValue).CGRectValue().height
    let duration = userInfo[UIKeyboardAnimationDurationUserInfoKey] as! Double
    let curve = userInfo[UIKeyboardAnimationCurveUserInfoKey] as! UInt
    let moveUp = (notification.name == UIKeyboardWillShowNotification)

    // baseContraint is your Auto Layout constraint that pins the
    // text view to the bottom of the superview.

    baseConstraint.constant = moveUp ? -keyboardHeight : 0

    let options = UIViewAnimationOptions(rawValue: curve << 16)
    UIView.animateWithDuration(duration, delay: 0, options: options,
        animations: {
            self.view.layoutIfNeeded()
        },
        completion: nil
    )

}

注意:这段代码涵盖了大多数注释/一般情况。然而,处理不同的方向和/或自定义键盘可能需要更多的代码。如果你需要处理每一个场景,这可能会有所帮助。