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")
}
}
Swift 5解决方案frédéric-adda:
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: UIResponder.keyboardWillShowNotification, object: nil, queue: nil) { [weak self] notification in
self?.keyboardWillShow(notification)
}
// Deal with rotations
NotificationCenter.default.addObserver(forName: UIResponder.keyboardWillChangeFrameNotification, object: nil, queue: nil) { [weak self] notification in
self?.keyboardWillShow(notification)
}
// Deal with keyboard change (emoji, numerical, etc.)
NotificationCenter.default.addObserver(forName: UITextInputMode.currentInputModeDidChangeNotification, object: nil, queue: nil) { [weak self] notification in
self?.keyboardWillShow(notification)
}
NotificationCenter.default.addObserver(forName: UIResponder.keyboardWillHideNotification, 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?[UIResponder.keyboardFrameEndUserInfoKey] 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)
}
}
在任何UIViewController中:
遵循KeyboardHandler协议
extension AnyViewController: KeyboardHandler {}
为屏幕上最后一个底部元素添加底部约束。
@IBOutlet var bottomConstraint: NSLayoutConstraint!
添加观察者订阅/取消订阅:
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
startObservingKeyboardChanges()
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
stopObservingKeyboardChanges()
}
享受吧!
struct MoveKeyboard {
static let KEYBOARD_ANIMATION_DURATION : CGFloat = 0.3
static let MINIMUM_SCROLL_FRACTION : CGFloat = 0.2;
static let MAXIMUM_SCROLL_FRACTION : CGFloat = 0.8;
static let PORTRAIT_KEYBOARD_HEIGHT : CGFloat = 216;
static let LANDSCAPE_KEYBOARD_HEIGHT : CGFloat = 162;
}
func textFieldDidBeginEditing(textField: UITextField) {
let textFieldRect : CGRect = self.view.window!.convertRect(textField.bounds, fromView: textField)
let viewRect : CGRect = self.view.window!.convertRect(self.view.bounds, fromView: self.view)
let midline : CGFloat = textFieldRect.origin.y + 0.5 * textFieldRect.size.height
let numerator : CGFloat = midline - viewRect.origin.y - MoveKeyboard.MINIMUM_SCROLL_FRACTION * viewRect.size.height
let denominator : CGFloat = (MoveKeyboard.MAXIMUM_SCROLL_FRACTION - MoveKeyboard.MINIMUM_SCROLL_FRACTION) * viewRect.size.height
var heightFraction : CGFloat = numerator / denominator
if heightFraction < 0.0 {
heightFraction = 0.0
} else if heightFraction > 1.0 {
heightFraction = 1.0
}
let orientation : UIInterfaceOrientation = UIApplication.sharedApplication().statusBarOrientation
if (orientation == UIInterfaceOrientation.Portrait || orientation == UIInterfaceOrientation.PortraitUpsideDown) {
animateDistance = floor(MoveKeyboard.PORTRAIT_KEYBOARD_HEIGHT * heightFraction)
} else {
animateDistance = floor(MoveKeyboard.LANDSCAPE_KEYBOARD_HEIGHT * heightFraction)
}
var viewFrame : CGRect = self.view.frame
viewFrame.origin.y -= animateDistance
UIView.beginAnimations(nil, context: nil)
UIView.setAnimationBeginsFromCurrentState(true)
UIView.setAnimationDuration(NSTimeInterval(MoveKeyboard.KEYBOARD_ANIMATION_DURATION))
self.view.frame = viewFrame
UIView.commitAnimations()
}
func textFieldDidEndEditing(textField: UITextField) {
var viewFrame : CGRect = self.view.frame
viewFrame.origin.y += animateDistance
UIView.beginAnimations(nil, context: nil)
UIView.setAnimationBeginsFromCurrentState(true)
UIView.setAnimationDuration(NSTimeInterval(MoveKeyboard.KEYBOARD_ANIMATION_DURATION))
self.view.frame = viewFrame
UIView.commitAnimations()
}
最后，因为我们使用委托方法
func textFieldShouldReturn(textField: UITextField) -> Bool {
textField.resignFirstResponder()
return true
}
使用objective-c重构http://www.cocoawithlove.com/2008/10/sliding-uitextfields-around-to-avoid.html
在现有的答案上有一些改进。
首先，uikeyboardwillchangeframeotification可能是最好的通知，因为它处理的变化不仅仅是显示/隐藏，而是由于键盘变化(语言，使用第三方键盘等)和旋转(但注意下面的评论表明键盘将隐藏也应该处理以支持硬件键盘连接)。
其次，动画参数可以从通知中提取，以确保动画正确地组合在一起。
可能有一些选项可以进一步清理此代码，特别是如果您对强制展开字典代码感到满意的话。
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()
NotificationCenter.default.addObserver(self,
selector: #selector(self.keyboardNotification(notification:)),
name: UIResponder.keyboardWillChangeFrameNotification,
object: nil)
}
deinit {
NotificationCenter.default.removeObserver(self)
}
@objc func keyboardNotification(notification: NSNotification) {
guard let userInfo = notification.userInfo else { return }
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)
}
}
