我正在使用Swift在iOS上进行编程,并且正在使用此代码移动UITextField,但是它不起作用。我keyboardWillShow正确调用了该函数,但是文本字段没有移动。我正在使用自动版式。
UITextField
keyboardWillShow
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") } }
现有答案有一些改进。
首先, UIKeyboardWillChangeFrameNotification 可能是最好的通知,因为它处理的不仅是显示/隐藏,还包括由于键盘更改(语言,使用第三方键盘等)和旋转引起的更改(但下面的注释说明指示键盘应隐藏)也可以处理以支持硬件键盘连接)。
其次,可以从通知中提取动画参数,以确保动画正确地在一起。
可能还有一些方法可以清理此代码,特别是如果您习惯于强制展开字典代码的话。
迅捷3
class MyViewController: UIViewController { // This constraint ties an element at zero points from the bottom layout guide @IBOutlet var keyboardHeightLayoutConstraint: NSLayoutConstraint? override func viewDidLoad() { super.viewDidLoad() // Note that SO highlighting makes the new selector syntax (#selector()) look // like a comment but it isn't one NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardNotification(notification:)), name: NSNotification.Name.UIKeyboardWillChangeFrame, object: nil) } deinit { NotificationCenter.default.removeObserver(self) } @objc func keyboardNotification(notification: NSNotification) { if let userInfo = notification.userInfo { let endFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue let endFrameY = endFrame.origin.y ?? 0 let duration:TimeInterval = (userInfo[UIKeyboardAnimationDurationUserInfoKey] as? NSNumber)?.doubleValue ?? 0 let animationCurveRawNSN = userInfo[UIKeyboardAnimationCurveUserInfoKey] as? NSNumber let animationCurveRaw = animationCurveRawNSN?.uintValue ?? UIViewAnimationOptions.curveEaseInOut.rawValue let animationCurve:UIViewAnimationOptions = UIViewAnimationOptions(rawValue: animationCurveRaw) if endFrameY >= UIScreen.main.bounds.size.height { self.keyboardHeightLayoutConstraint?.constant = 0.0 } else { self.keyboardHeightLayoutConstraint?.constant = endFrame?.size.height ?? 0.0 } UIView.animate(withDuration: duration, delay: TimeInterval(0), options: animationCurve, animations: { self.view.layoutIfNeeded() }, completion: nil) } }
(根据@Gabox的出色注释,编辑后考虑了键盘动画在屏幕外而不是缩小)
斯威夫特5
class MyViewController: UIViewController { // This constraint ties an element at zero points from the bottom layout guide @IBOutlet var keyboardHeightLayoutConstraint: NSLayoutConstraint? override func viewDidLoad() { super.viewDidLoad() // Note that SO highlighting makes the new selector syntax (#selector()) look // like a comment but it isn't one NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardNotification(notification:)), name: UIResponder.keyboardWillChangeFrameNotification, object: nil) } deinit { NotificationCenter.default.removeObserver(self) } @objc func keyboardNotification(notification: NSNotification) { if let userInfo = notification.userInfo { let endFrame = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue let endFrameY = endFrame?.origin.y ?? 0 let duration:TimeInterval = (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 = UIView.AnimationOptions(rawValue: animationCurveRaw) if endFrameY >= UIScreen.main.bounds.size.height { self.keyboardHeightLayoutConstraint?.constant = 0.0 } else { self.keyboardHeightLayoutConstraint?.constant = endFrame?.size.height ?? 0.0 } UIView.animate(withDuration: duration, delay: TimeInterval(0), options: animationCurve, animations: { self.view.layoutIfNeeded() }, completion: nil) } }