NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
func keyboardWillHide(notification: NSNotification) {
if let rect = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
}
}
By the way, function does not give correct RectValue.
Whats wrong with this?
Try this:
NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
func keyboardWillHide(notification: NSNotification) {
if let rect = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
}
}
func keyboardWillShow(notification: NSNotification) {
if let rect = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
}
}
Related
I've got a UITableviewController with following logic to slide up / down the entire view once the keyboard toggles like so:
class ChatDetailViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
// variables...
override func viewDidLoad() {
super.viewDidLoad()
// do stuff...
NotificationCenter.default.addObserver(self, selector: Selector(("keyboardWillShow:")), name: UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: Selector(("keyboardWillHide:")), name: UIResponder.keyboardWillHideNotification, object: nil)
// do other stuff...
}
...
func keyboardWillShow(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
self.view.frame.origin.y -= keyboardSize.height
}
}
func keyboardWillHide(notification: NSNotification) {
self.view.frame.origin.y = 0
}
...
}
Toggling the keyboard then crashes the App with following exception: ChatDetailViewController keyboardWillShow:]: unrecognized selector sent to instance 0x7f82fc41fdf0
The error message seems clear at first glance but I still can't figure out what's wrong with my selector. No code warnings, no typos,...
What is it I'm doing wrong here?
In Swift 4 i have previously used in like this
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}
#objc func keyboardWillShow(notification: NSNotification) {
print("keyboardWillShow")
}
#objc func keyboardWillHide(notification: NSNotification){
print("keyboardWillHide")
}
In Swift 5 they renamed the way to access the keyboard notifications to go through UIResponder:
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillShow), name: UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillHide), name: UIResponder.keyboardWillHideNotification, object: nil)
}
Three issues:
The creation of the selector is wrong (use #selector)
The signature of the action is wrong (missing underscore)
The action must be marked as #objc
And the type in Swift is Notification without NS prefix
override func viewDidLoad() {
super.viewDidLoad()
// do stuff...
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name: UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name: UIResponder.keyboardWillHideNotification, object: nil)
// do other stuff...
}
...
#objc func keyboardWillShow(_ notification: Notification) {
if let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
self.view.frame.origin.y -= keyboardSize.height
}
}
#objc func keyboardWillHide(_ notification: Notification) {
self.view.frame.origin.y = 0
}
...
You forgot to add #objc part:
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(_ sender: Notification) {}
#objc func keyboardWillHide(_ sender: Notification) {}
If I try to tap into my textfields I get an error, related to these few lines of code that try to get the size of the keyboard on a mobile ios device. The Notification Center lines of code are inside the overriding ViewDidAppear.
NotificationCenter.default.addObserver(self, selector: Selector(("keyboardWillShow:")), name: UIResponder.keyboardDidShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: Selector(("keyboardWillHide:")), name: UIResponder.keyboardDidHideNotification, object: nil)
func keyboardWillShow(notification: NSNotification) {
if let userInfo = notification.userInfo {
if let keyboardSize = (userInfo[UIResponder.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
self.bottomConstraint.constant = keyboardSize.height
}
}
}
func keyboardWillHide(notification: NSNotification) {
self.bottomConstraint.constant = 0
}
Use the type safe syntax
#selector(keyboardWillShow)
and
#objc func keyboardWillShow(_ notification: Notification) { ...
However I highly recommend to use the modern closure based syntax
NotificationCenter.default.addObserver(forName: UIResponder.keyboardWillShowNotification, object: nil, queue: .main) { [weak self] notification in
if let userInfo = notification.userInfo,
let keyboardSize = (userInfo[UIResponder.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
self?.bottomConstraint.constant = keyboardSize.height
}
}
NotificationCenter.default.addObserver(forName: UIResponder.keyboardWillHideNotification, object: nil, queue: .main) { [weak self] _ in
self?.bottomConstraint.constant = 0
}
Try Following code :
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.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
print("notification: Keyboard will show")
}
}
#objc func keyboardWillHide(notification: Notification) {
if let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
}
}
You can try this:
This code in viewDidLoad():
// Do any additional setup after loading the view.
NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
and then add this in ViewController
#objc func keyboardWillShow(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
print("Keyboard opened \(keyboardSize)")
}
}
#objc func keyboardWillHide(notification: NSNotification) {
print("Keyboard hide")
}
Hope this will help.
You should deregister any notification you register in a view.
func registerForKeyboardNotifications()
{
//Adding notifies on keyboard appearing
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWasShown(_:)), name: UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillBeHidden(_:)), name: UIResponder.keyboardWillHideNotification, object: nil)
}
func deRegisterFromKeyboardNotifications()
{
//Removing notifies on keyboard appearing
NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillHideNotification, object: nil)
}
#objc func keyboardWasShown(_ notification: NSNotification)
{
//todo
}
#objc func keyboardWillBeHidden(_ notification: NSNotification)
{
//todo
}
override func viewDidLoad() {
super.viewDidLoad()
registerForKeyboardNotifications()
}
override func viewDidDisappear(_ animated: Bool) {
super.viewDidDisappear(animated)
deRegisterFromKeyboardNotifications()
}
You've got this error because of notification parameter. With current signature you should use:
#selector(keyboardWillShow(notification:))
#selector(keyboardWillHide(notification:))
Or rewrite your methods in that way:
#objc func keyboardWillShow(_ notification: Notification) {
// Code
}
#objc func keyboardWillHide(_ notification: Notification) {
// Code
}
And use the next syntax:
#selector(keyboardWillShow(_:))
#selector(keyboardWillHide(_:))
Edited:
You can also use simplified syntax:
#selector(keyboardWillShow)
#selector(keyboardWillHide)
Use like below code
NotificationCenter.default.addObserver(self,
selector: #selector(keyboardWillShow(notification:)),
name: UIResponder.keyboardWillShowNotification,
object: nil)
NotificationCenter.default.addObserver(self,
selector: #selector(keyboardWillHide(notification:)),
name: UIResponder.keyboardWillHideNotification,
object: nil)
#objc func keyboardWillShow(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
// Your code
}
}
#objc func keyboardWillHide(notification: NSNotification) {
// Your code
}
Hope this works, If any doubt plz comment.
I have a textview and a text field on my screen and I want move screen when edit textview.
This is my code
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(_:)), name: .UIKeyboardWillShow, object: nil)
// NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(_:)), name: .UIKeyboardWillHide, object: nil)
print("addd observer")
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
NotificationCenter.default.removeObserver(self, name: .UIKeyboardWillShow, object: nil)
// NotificationCenter.default.removeObserver(self, name: .UIKeyboardWillHide, object: nil)
}
#objc func keyboardWillShow(_ sender: Notification) {
let keyboardSize = (sender.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue
print("keyboardwillshow")
ksize = keyboardSize?.height
}
#objc func textViewDidBeginEditing(_ textView: UITextView) {
print("textviewedit")
boxview.frame.origin.y -= ksize
print("textview")
}
#objc func textViewDidEndEditing(_ textView: UITextView) {
print("textvieweditend")
boxview.frame.origin.y = 0
}
It works when I just edit textview. However, if I edit the textview right after focus on the textfield(without exit keyboard) it doens't work.
I already checked that textviewDidBeginEditing() is called but the screen doesn't move.. How can I solve this? All advises are welcome!
I add self.view.Layoutifneeded() to keyboardwillchange() and it works!! thanks everybody.
I have a very small question - can we calculate the Keyboard Height with out using Notification. All the answers in stake overflow is using NSNotification but is there simpler way of calculating it?
below is the code:
NotificationCenter.default.addObserver( self, selector: #selector(keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil
#objc func keyboardWillShow(notification: ) {
if let userInfo = notification.userInfo {
if let keyboardSize = (userInfo[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
let kbHeight = keyboardSize.height
}
}
}
Code to use keyboard height in textFieldDidBeginEditing:
var kbHeight: CGFloat?
#objc func keyboardWillShow(notification: NSNotification) {
if let userInfo = notification.userInfo {
if let keyboardSize = (userInfo[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
kbHeight = keyboardSize.height
}
}
}
func textFieldDidBeginEditing(_ textField: UITextField) {
if textField.frame.maxY > self.kbHeight!
{
self.scrollView.setContentOffset(CGPoint.init(x: 0, y: textField.frame.maxY - (self.kbHeight! + 2.0)), animated: true)
}
else{
return
}
print(textField.frame.maxY)
print(self.view.frame.height * 0.6)
print(textField.frame.maxY - self.view.frame.height * 0.6)
}
func textFieldDidEndEditing(_ textField: UITextField)
{
self.scrollView.setContentOffset(CGPoint.init(x: 0, y: 0), animated: true)
self.view.endEditing(true);
}
actually i don't have any idea for getting keyboard hight directly.. but you can save the keyboard height in variable when keyboard is present and use them where you want
Use these two Observers for keyboard and manage the keyboard hight
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
Must be remove these observer at dinit method when pop or dismiss the view controller.
deinit {
NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}
Selector methods for keyboard notification ...
#objc func keyboardWillShow(notification: NSNotification) {
var keyBoardHeight: CGFloat = 0
if let keyboardFrame: NSValue = notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue {
let keyboardRectangle = keyboardFrame.cgRectValue
keyBoardHeight = keyboardRectangle.height
}
}
#objc func keyboardWillHide(notification: NSNotification) {
}
I'm trying to add a simple keyboard notification, but receive a "EXC_BAD_INSTRUCTION" error whenever I run the code. Any help is appreciated.
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyBoardWillShow:", name: UIKeyboardWillShowNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyBoardWillHide:", name: UIKeyboardWillHideNotification, object: nil)
func keyBoardWillShow(notification: NSNotification) {
var info:NSDictionary = notification.userInfo!
var keyboardSize = (info[UIKeyboardFrameBeginUserInfoKey] as NSValue).CGRectValue()
var keyboardHeight:CGFloat = keyboardSize.height - 40
var animationDuration:CGFloat = info[UIKeyboardAnimationDurationUserInfoKey] as CGFloat
var contentInsets: UIEdgeInsets = UIEdgeInsetsMake(0.0, 0.0, keyboardHeight, 0.0);
self.tableView.contentInset = contentInsets
self.tableView.scrollIndicatorInsets = contentInsets
}
func keyBoardWillHide(notification: NSNotification) {
self.tableView.contentInset = UIEdgeInsetsZero
self.tableView.scrollIndicatorInsets = UIEdgeInsetsZero
}
Change your top two lines from :
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyBoardWillShow:", name: UIKeyboardWillShowNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyBoardWillHide:", name: UIKeyboardWillHideNotification, object: nil)
to :
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillShow:"), name:UIKeyboardWillShowNotification, object: nil);
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("keyboardWillHide:"), name:UIKeyboardWillHideNotification, object: nil);
Notice the Selector("nameoftheFunction:") syntax in swift
import UIKit
import CoreData
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillShowNotification, object: nil)
NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillHideNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyBoardWillShow:", name: UIKeyboardWillShowNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyBoardWillHide:", name: UIKeyboardWillHideNotification, object: nil)
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func keyBoardWillShow(notification: NSNotification) {
var info:NSDictionary = notification.userInfo!
var keyboardSize = (info[UIKeyboardFrameBeginUserInfoKey] as NSValue).CGRectValue()
var keyboardHeight:CGFloat = keyboardSize.height - 40
var animationDuration:CGFloat = info[UIKeyboardAnimationDurationUserInfoKey] as CGFloat
var contentInsets: UIEdgeInsets = UIEdgeInsetsMake(0.0, 0.0, keyboardHeight, 0.0);
self.tableView.contentInset = contentInsets
self.tableView.scrollIndicatorInsets = contentInsets
}
func keyBoardWillHide(notification: NSNotification) {
self.tableView.contentInset = UIEdgeInsetsZero
self.tableView.scrollIndicatorInsets = UIEdgeInsetsZero
}
}