我试图在键盘显示和消失时运行一个函数,并具有以下代码:
let notificationCenter = NotificationCenter.default
notificationCenter.addObserver(self, selector: #selector(ViewController.keyBoardUp(Notification :)), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
以下功能keyBoardUp
:
func keyBoardUp( Notification: NSNotification){
print("HELLO")
}
但是,当键盘显示时,该功能不会打印到控制台。非常感谢帮助
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(ViewController.keyboardWillShow), name: Notification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(ViewController.keyboardWillHide), name: Notification.Name.UIKeyboardWillHide, object: nil)
}
func keyboardWillShow(notification: Notification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
print("notification: Keyboard will show")
if self.view.frame.origin.y == 0{
self.view.frame.origin.y -= keyboardSize.height
}
}
}
func keyboardWillHide(notification: Notification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
if self.view.frame.origin.y != 0 {
self.view.frame.origin.y += keyboardSize.height
}
}
}
@vandana's答案已更新,以反映Swift 4.2中对本机通知的更改。
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(ViewController.keyboardWillShow), name: UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(ViewController.keyboardWillHide), name: UIResponder.keyboardWillHideNotification, object: nil)
}
@objc func keyboardWillShow(notification: Notification) {
if let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
print("notification: Keyboard will show")
if self.view.frame.origin.y == 0{
self.view.frame.origin.y -= keyboardSize.height
}
}
}
@objc func keyboardWillHide(notification: Notification) {
if let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
if self.view.frame.origin.y != 0 {
self.view.frame.origin.y += keyboardSize.height
}
}
}
此外,您需要使用UIKeyboardFrameEndUserInfoKey
来解释iOS 11引入的safeAreaInset
更改。
设置键盘通知观察器
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardNotification(notification:)), name: NSNotification.Name.UIKeyboardDidShow, object: nil)
}
并在您的函数中处理它
func keyboardNotification(notification: NSNotification) {
print("keyboard displayed!!")
}
希望这会帮助你。
更新为swift:
// MARK:- Kyeboard hide/show methods
func keyboardWasShown(_ notification: Notification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
if self.view.frame.origin.y == 0{
self.view.frame.origin.y -= keyboardSize.height
}
}
}
func keyboardWillBeHidden(_ notification: Notification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
if self.view.frame.origin.y != 0{
self.view.frame.origin.y += keyboardSize.height
}
}
}
func registerForKeyboardNotifications(){
//Adding notifies on keyboard appearing
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWasShown(_:)), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillBeHidden(_:)), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}
func deregisterFromKeyboardNotifications(){
//Removing notifies on keyboard appearing
NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}
func textFieldDidBeginEditing(_ textField: UITextField) {
if textField == mEnterPasswordTextField || textField == mEnterConfirmPassword {
animateViewMoving(up: true, moveValue: 120)
}
}
func textFieldDidEndEditing(_ textField: UITextField) {
if textField == mEnterPasswordTextField || textField == mEnterConfirmPassword {
animateViewMoving(up: false, moveValue: 120)
}
}
func animateViewMoving (up:Bool, moveValue :CGFloat){
let movementDuration:TimeInterval = 0.3
let movement:CGFloat = ( up ? -moveValue : moveValue)
UIView.beginAnimations( "animateView", context: nil)
UIView.setAnimationBeginsFromCurrentState(true)
UIView.setAnimationDuration(movementDuration )
self.view.frame = self.view.frame.offsetBy(dx: 0, dy: movement)
UIView.commitAnimations()
}
//在viewDidLoad()中
self.registerForKeyboardNotifications()
self.deregisterFromKeyboardNotifications()
试试这个
override func viewDidLoad()
{
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillShow(notification:)), name: NSNotification.Name.UIKeyboardDidShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillHide(notification:)), name: NSNotification.Name.UIKeyboardDidHide, object: nil)
}
@objc func keyboardWillShow(notification: NSNotification) {
if(messageCount > 0)
{
tableView.scrollToRow(at: IndexPath(item:messageCount - 1, section: 0), at: .bottom, animated: true)
}
}
@objc func keyboardWillHide(notification: NSNotification) {
if(messageCount > 0)
{
tableView.scrollToRow(at: IndexPath(item:0, section: 0), at: .top, animated: true)
}
}
Swift 4.2
NotificationCenter.default.addObserver(self, selector: #selector(didReceiveKeyboardNotificationObserver(_:)), name: UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(didReceiveKeyboardNotificationObserver(_:)), name: UIResponder.keyboardWillHideNotification, object: nil)
@objc func didReceiveKeyboardNotificationObserver(_ notification: Notification) {
let userInfo = notification.userInfo
let keyboardBounds = (userInfo!["UIKeyboardBoundsUserInfoKey"] as! NSValue).cgRectValue
let keyboardFrame = (userInfo!["UIKeyboardFrameEndUserInfoKey"] as! NSValue).cgRectValue
let duration = userInfo!["UIKeyboardAnimationDurationUserInfoKey"] as! Double
let curve = userInfo!["UIKeyboardAnimationCurveUserInfoKey"] as! Int
let frameBegin = (userInfo!["UIKeyboardFrameBeginUserInfoKey"] as! NSValue).cgRectValue
let centerBegin = (userInfo!["UIKeyboardCenterBeginUserInfoKey"] as! NSValue).cgPointValue
let center = (userInfo!["UIKeyboardCenterEndUserInfoKey"] as! NSValue).cgPointValue
let location = userInfo!["UIKeyboardIsLocalUserInfoKey"] as! Int
println("keyboardBounds: \(keyboardBounds) \nkeyboardFrame: \(keyboardFrame) \nduration: \(duration) \ncurve: \(curve) \nframeBegin:\(frameBegin) \ncenterBegin:\(centerBegin)\ncenter:\(center)\nlocation:\(location)")
switch notification.name {
case UIResponder.keyboardWillShowNotification:
// keyboardWillShowNotification
case UIResponder.keyboardWillHideNotification:
// keyboardWillHideNotification
default:
break
}
}
我喜欢内联,基于块的方法,已经有很长一段时间了!您可以阅读更多关于addObserver(...)
here的参数。
这种方法的一些优点是:
重要提示:在您设置注册观察者的对象(通常是视图控制器)的
NotificationCenter.default.removeObserver(observer)
中调用deinit
。
let center = NotificationCenter.default
let keyboardWillShowObserver: NSObjectProtocol = center.addObserver(forName: UIResponder.keyboardWillShowNotification, object: nil, queue: nil) { (notification) in
guard let value = notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue else { return }
let height = value.cgRectValue.height
// use the height of the keyboard to layout your UI so the prt currently in
// foxus remains visible
}
let keyboardWillHideObserver: NSObjectProtocol = center.addObserver(forName: UIResponder.keyboardWillShowNotification, object: nil, queue: nil) { (notification) in
// restore the layout of your UI before the keyboard has been shown
}
此版本适用于iPhone 5和iPhone X.如果您在约束设置期间尊重安全区域,它的效果非常好。
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name: UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name: UIResponder.keyboardWillHideNotification, object: nil)
}
@objc func keyboardWillShow(notification: NSNotification) {
if let _ = (notification.userInfo?[UIResponder.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
self.view.frame.origin.y = self.navigationController!.navigationBar.frame.size.height + UIApplication.shared.statusBarFrame.size.height
if self.emailTextField.isFirstResponder {
self.view.frame.origin.y -= 100
} else if self.passwordTextField.isFirstResponder {
self.view.frame.origin.y -= 150
} else if self.passwordConfirmTextField.isFirstResponder {
self.view.frame.origin.y -= 200
}
}
}
@objc func keyboardWillHide(notification: NSNotification) {
if self.view.frame.origin.y != 0 {
self.view.frame.origin.y = self.navigationController!.navigationBar.frame.size.height + UIApplication.shared.statusBarFrame.size.height
}
}