How do I scroll the UIScrollView when the keyboard appears?
I'm having trouble with my code. I'm trying to move the UIScrollView
when I'm editing an UITextField
that should be hidden by the keyboard pop.
I'm moving the main frame right now because I don't know how to 'scroll up' in the code.
So, I did a little bit of code, it's working fine but when I edit an UItextfield and I switch to another UITextField
without pressing on the 'return' button the main view goes waaayyyyy to far up.
I did an NSLog()
with my variables size, distance and textFieldRect.origin.y as you can see below. When I put two UITextField
at the same place (y origin) and I do this particular 'switch' (wihtout pressing return) , I get the same numbers, whereas my code worked fine for the first UITextField
editing but not for the second editing.
Check this out:
- (void)textFieldDidBeginEditing:(UITextField *)textField {
{
int size;
CGRect textFieldRect = [self.view.window convertRect:textField.bounds fromView:textField];
size = textFieldRect.origin.y + textFieldRect.size.height;
if (change == FALSE)
{
size = size - distance;
}
if (size < PORTRAIT_KEYBOARD_HEIGHT)
{
distance = 0;
}
else if (size > PORTRAIT_KEYBOARD_HEIGHT)
{
distance = size - PORTRAIT_KEYBOARD_HEIGHT + 5; // +5 px for more visibility
}
NSLog(@"origin %f", textFieldRect.origin.y);
NSLog(@"size %d", size);
NSLog(@"distance %d", distance);
CGRect viewFrame = self.view.frame;
viewFrame.origin.y -= distance;
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView setAnimationDuration:KEYBOARD_ANIMATION_DURATION];
[self.view setFrame:viewFrame];
[UIView commitAnimations];
change = FALSE;
}
- (void)textFieldDidEndEditing:(UITextField *)textField
{
change = TRUE;
CGRect viewFrame = self.view.frame;
viewFrame.origin.y += distance;
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView setAnimationDuration:KEYBOARD_ANIMATION_DURATION];
[self.view setFrame:viewFrame];
[UIView commitAnimations];
}
Any ideas ?
Solution 1:
The recommended way from Apple is to change the contentInset
of the UIScrollView
. It is a very elegant solution, because you do not have to mess with the contentSize
.
Following code is copied from the Keyboard Programming Guide, where the handling of this issue is explained. You should have a look into it.
// Call this method somewhere in your view controller setup code.
- (void)registerForKeyboardNotifications
{
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardWasShown:)
name:UIKeyboardDidShowNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(keyboardWillBeHidden:)
name:UIKeyboardWillHideNotification object:nil];
}
// Called when the UIKeyboardDidShowNotification is sent.
- (void)keyboardWasShown:(NSNotification*)aNotification
{
NSDictionary* info = [aNotification userInfo];
CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
UIEdgeInsets contentInsets = UIEdgeInsetsMake(0.0, 0.0, kbSize.height, 0.0);
scrollView.contentInset = contentInsets;
scrollView.scrollIndicatorInsets = contentInsets;
// If active text field is hidden by keyboard, scroll it so it's visible
// Your application might not need or want this behavior.
CGRect aRect = self.view.frame;
aRect.size.height -= kbSize.height;
if (!CGRectContainsPoint(aRect, activeField.frame.origin) ) {
CGPoint scrollPoint = CGPointMake(0.0, activeField.frame.origin.y-kbSize.height);
[scrollView setContentOffset:scrollPoint animated:YES];
}
}
// Called when the UIKeyboardWillHideNotification is sent
- (void)keyboardWillBeHidden:(NSNotification*)aNotification
{
UIEdgeInsets contentInsets = UIEdgeInsetsZero;
scrollView.contentInset = contentInsets;
scrollView.scrollIndicatorInsets = contentInsets;
}
Swift version:
func registerForKeyboardNotifications() {
NotificationCenter.default.addObserver(self, selector: #selector(onKeyboardAppear(_:)), name: NSNotification.Name.UIKeyboardDidShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(onKeyboardDisappear(_:)), name: NSNotification.Name.UIKeyboardDidHide, object: nil)
}
// Don't forget to unregister when done
deinit {
NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardDidShow, object: nil)
NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardDidHide, object: nil)
}
@objc func onKeyboardAppear(_ notification: NSNotification) {
let info = notification.userInfo!
let rect: CGRect = info[UIKeyboardFrameBeginUserInfoKey] as! CGRect
let kbSize = rect.size
let insets = UIEdgeInsetsMake(0, 0, kbSize.height, 0)
scrollView.contentInset = insets
scrollView.scrollIndicatorInsets = insets
// If active text field is hidden by keyboard, scroll it so it's visible
// Your application might not need or want this behavior.
var aRect = self.view.frame;
aRect.size.height -= kbSize.height;
let activeField: UITextField? = [addressTextView, servicePathTextView, usernameTextView, passwordTextView].first { $0.isFirstResponder }
if let activeField = activeField {
if !aRect.contains(activeField.frame.origin) {
let scrollPoint = CGPoint(x: 0, y: activeField.frame.origin.y-kbSize.height)
scrollView.setContentOffset(scrollPoint, animated: true)
}
}
}
@objc func onKeyboardDisappear(_ notification: NSNotification) {
scrollView.contentInset = UIEdgeInsets.zero
scrollView.scrollIndicatorInsets = UIEdgeInsets.zero
}
Solution 2:
I just implemented this with Swift 2.0 for iOS9 on Xcode 7 (beta 6), works fine here.
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
registerKeyboardNotifications()
}
func registerKeyboardNotifications() {
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillShow:", name: UIKeyboardWillShowNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillHide:", name: UIKeyboardWillHideNotification, object: nil)
}
deinit {
NSNotificationCenter.defaultCenter().removeObserver(self)
}
func keyboardWillShow(notification: NSNotification) {
let userInfo: NSDictionary = notification.userInfo!
let keyboardSize = userInfo.objectForKey(UIKeyboardFrameBeginUserInfoKey)!.CGRectValue.size
let contentInsets = UIEdgeInsetsMake(0, 0, keyboardSize.height, 0)
scrollView.contentInset = contentInsets
scrollView.scrollIndicatorInsets = contentInsets
var viewRect = view.frame
viewRect.size.height -= keyboardSize.height
if CGRectContainsPoint(viewRect, textField.frame.origin) {
let scrollPoint = CGPointMake(0, textField.frame.origin.y - keyboardSize.height)
scrollView.setContentOffset(scrollPoint, animated: true)
}
}
func keyboardWillHide(notification: NSNotification) {
scrollView.contentInset = UIEdgeInsetsZero
scrollView.scrollIndicatorInsets = UIEdgeInsetsZero
}
Edited for Swift 3
Seems like you only need to set the contentInset
and scrollIndicatorInset
with Swift 3, the scrolling/contentOffset is done automatically..
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
registerKeyboardNotifications()
}
func registerKeyboardNotifications() {
NotificationCenter.default.addObserver(self,
selector: #selector(keyboardWillShow(notification:)),
name: NSNotification.Name.UIKeyboardWillShow,
object: nil)
NotificationCenter.default.addObserver(self,
selector: #selector(keyboardWillHide(notification:)),
name: NSNotification.Name.UIKeyboardWillHide,
object: nil)
}
deinit {
NotificationCenter.default.removeObserver(self)
}
func keyboardWillShow(notification: NSNotification) {
let userInfo: NSDictionary = notification.userInfo! as NSDictionary
let keyboardInfo = userInfo[UIKeyboardFrameBeginUserInfoKey] as! NSValue
let keyboardSize = keyboardInfo.cgRectValue.size
let contentInsets = UIEdgeInsets(top: 0, left: 0, bottom: keyboardSize.height, right: 0)
scrollView.contentInset = contentInsets
scrollView.scrollIndicatorInsets = contentInsets
}
func keyboardWillHide(notification: NSNotification) {
scrollView.contentInset = .zero
scrollView.scrollIndicatorInsets = .zero
}
Solution 3:
Swift 5 Solution:
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
registerKeyboardNotifications()
}
func registerKeyboardNotifications() {
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)
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
NotificationCenter.default.removeObserver(self)
}
@objc func keyboardWillShow(notification: NSNotification) {
let userInfo: NSDictionary = notification.userInfo! as NSDictionary
let keyboardInfo = userInfo[UIResponder.keyboardFrameBeginUserInfoKey] as! NSValue
let keyboardSize = keyboardInfo.cgRectValue.size
let contentInsets = UIEdgeInsets(top: 0, left: 0, bottom: keyboardSize.height, right: 0)
scrollView.contentInset = contentInsets
scrollView.scrollIndicatorInsets = contentInsets
}
@objc func keyboardWillHide(notification: NSNotification) {
scrollView.contentInset = .zero
scrollView.scrollIndicatorInsets = .zero
}