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")
}
}
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
}
}
编辑:我推荐一个更简单、更干净的解决方案。只需将底部间距约束的类更改为KeyboardLayoutConstraint。它会自动展开到键盘高度。
这是一个改进版的@JosephLord的回答。
在iOS 8.3 iPad模拟器上测试,Portrait。Xcode6.3 beta4,我发现他的答案不工作时,键盘隐藏,因为UIKeyboardFrameEndUserInfoKey是“NSRect:{{0, 1024},{768, 264}}”;高度不为0。
这回到使用传统的UIKeyboardWillShowNotification和UIKeyboardWillHideNotification来更好地判断键盘何时隐藏,而不是依赖于结束帧的高度。UIKeyboardWillShowNotification也会在键盘帧改变时发送,所以它应该覆盖所有的用例。
// You have to set this up in storyboard first!.
// It's a vertical spacing constraint between view and bottom of superview.
@IBOutlet weak var bottomSpacingConstraint: NSLayoutConstraint!
override func viewDidLoad() {
super.viewDidLoad()
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardNotification:"), name:UIKeyboardWillShowNotification, object: nil);
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardNotification:"), name:UIKeyboardWillHideNotification, object: nil);
}
deinit {
NSNotificationCenter.defaultCenter().removeObserver(self)
}
func keyboardNotification(notification: NSNotification) {
let isShowing = notification.name == UIKeyboardWillShowNotification
if let userInfo = notification.userInfo {
let endFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.CGRectValue()
let endFrameHeight = endFrame?.size.height ?? 0.0
let duration:NSTimeInterval = (userInfo[UIKeyboardAnimationDurationUserInfoKey] as? NSNumber)?.doubleValue ?? 0
let animationCurveRawNSN = userInfo[UIKeyboardAnimationCurveUserInfoKey] as? NSNumber
let animationCurveRaw = animationCurveRawNSN?.unsignedLongValue ?? UIViewAnimationOptions.CurveEaseInOut.rawValue
let animationCurve:UIViewAnimationOptions = UIViewAnimationOptions(rawValue: animationCurveRaw)
self.bottomSpacingConstraint?.constant = isShowing ? endFrameHeight : 0.0
UIView.animateWithDuration(duration,
delay: NSTimeInterval(0),
options: animationCurve,
animations: { self.view.layoutIfNeeded() },
completion: nil)
}
}
我修改了一点@Simpa解决方案.........
override func viewDidLoad()
{
super.viewDidLoad()
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("makeSpaceForKeyboard:"), name:UIKeyboardWillShowNotification, object: nil);
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("makeSpaceForKeyboard:"), name:UIKeyboardWillHideNotification, object: nil);
}
deinit{
NSNotificationCenter.defaultCenter().removeObserver(self)
}
var keyboardIsVisible = false
override func makeSpaceForKeyboard(notification: NSNotification) {
let info = notification.userInfo!
let keyboardHeight:CGFloat = (info[UIKeyboardFrameEndUserInfoKey] as! NSValue).CGRectValue().size.height
let duration:Double = info[UIKeyboardAnimationDurationUserInfoKey] as! Double
if notification.name == UIKeyboardWillShowNotification && keyboardIsVisible == false{
keyboardIsVisible = true
UIView.animateWithDuration(duration, animations: { () -> Void in
var frame = self.view.frame
frame.size.height = frame.size.height - keyboardHeight
self.view.frame = frame
})
} else if keyboardIsVisible == true && notification.name == UIKeyboardWillShowNotification{
}else {
keyboardIsVisible = false
UIView.animateWithDuration(duration, animations: { () -> Void in
var frame = self.view.frame
frame.size.height = frame.size.height + keyboardHeight
self.view.frame = frame
})
}
}
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!