Comment faire défiler l'UIScrollView lorsque le clavier apparaît ?

Question

J'ai des problèmes avec mon code. J'essaie de déplacer le UIScrollView lorsque j'édite un UITextField qui devrait être caché par le pop du clavier.

Je suis en train de déplacer le cadre principal parce que je ne sais pas comment faire défiler les pages vers le haut dans le code. Donc, j'ai fait un peu de code, ça marche bien mais quand je modifie un champ UItext et que je passe à un autre champ UItext UITextField sans appuyer sur le bouton 'retour' la vue principale monte beaucoup trop haut.

J'ai fait un NSLog() avec mes variables size, distance et textFieldRect.origin.y comme vous pouvez le voir ci-dessous. Lorsque je mets deux UITextField au même endroit (origine y) et que je fais ce 'switch' particulier (sans appuyer sur retour), j'obtiens les mêmes chiffres, alors que mon code fonctionnait bien pour le premier UITextField mais pas pour la deuxième édition.

Regarde ça :

- (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];
}

Des idées ?

Answer 1

La recommandation d'Apple recodée en Swift + Utiliser UIScrollView avec Auto Layout dans iOS (en se basant sur les liens suivants) : lien 1 , lien 2 , lien 3 ) :

import UIKit

class ViewController: UIViewController, UITextFieldDelegate {

    @IBOutlet var t1: UITextField!
    @IBOutlet var t2: UITextField!
    @IBOutlet var t3: UITextField!
    @IBOutlet var t4: UITextField!

    @IBOutlet var srcScrollView: UIScrollView!

    @IBOutlet var contentView: UIView!

    var contentViewCoordinates: CGPoint!

    override func viewDidLoad() {

        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        /* Constraints on content view */
        let leftConstraint = NSLayoutConstraint(item:self.contentView,
            attribute:NSLayoutAttribute.Leading,
            relatedBy:NSLayoutRelation.Equal,
            toItem:self.view,
            attribute:NSLayoutAttribute.Left,
            multiplier:1.0,
            constant:0)
        self.view.addConstraint(leftConstraint)

        let rightConstraint = NSLayoutConstraint(item:self.contentView,
            attribute:NSLayoutAttribute.Trailing,
            relatedBy:NSLayoutRelation.Equal,
            toItem:self.view,
            attribute:NSLayoutAttribute.Right,
            multiplier:1.0,
            constant:0)
        self.view.addConstraint(rightConstraint)

        /* Tap gesture */
        let tapGesture: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: "hideKeyboard")
        // prevents the scroll view from swallowing up the touch event of child buttons
        tapGesture.cancelsTouchesInView = false
        srcScrollView.addGestureRecognizer(tapGesture)

        /* Save content view coordinates */
        contentViewCoordinates = contentView.frame.origin
    }

    func hideKeyboard() {
        t1.resignFirstResponder()
        t2.resignFirstResponder()
        t3.resignFirstResponder()
        t4.resignFirstResponder()
    }

    var activeField: UITextField?

    func textFieldDidBeginEditing(textField: UITextField) {
        activeField = textField
    }

    func textFieldDidEndEditing(textField: UITextField) {
        activeField = nil
    }

    override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated)
        let center = NSNotificationCenter.defaultCenter()
        center.addObserver(self, selector: "keyboardOnScreen:", name: UIKeyboardDidShowNotification, object: nil)
        center.addObserver(self, selector: "keyboardOffScreen:", name: UIKeyboardDidHideNotification, object: nil)
    }

    func keyboardOnScreen(notification: NSNotification){
        // Retrieve the size and top margin (inset is the fancy word used by Apple) 
        // of the keyboard displayed.
        let info: NSDictionary  = notification.userInfo!
        let kbSize = info.valueForKey(UIKeyboardFrameEndUserInfoKey)?.CGRectValue().size
        let contentInsets: UIEdgeInsets  = UIEdgeInsetsMake(0.0, 0.0, kbSize!.height, 0.0)

        srcScrollView.contentInset = contentInsets
        srcScrollView.scrollIndicatorInsets = contentInsets

        var aRect: CGRect = self.view.frame
        aRect.size.height -= kbSize!.height
        //you may not need to scroll, see if the active field is already visible
        if (CGRectContainsPoint(aRect, activeField!.frame.origin) == false) {
            let scrollPoint:CGPoint = CGPointMake(0.0, activeField!.frame.origin.y - kbSize!.height)
            srcScrollView.setContentOffset(scrollPoint, animated: true)
        }
    }

//    func keyboardOnScreen(aNotification: NSNotification) {
//        let info: NSDictionary  = aNotification.userInfo!
//        let kbSize = info.valueForKey(UIKeyboardFrameEndUserInfoKey)?.CGRectValue().size
//        
//        var bkgndRect: CGRect! = activeField?.superview?.frame
//        
//        bkgndRect.size.height += kbSize!.height
//        
//        activeField?.superview?.frame = bkgndRect
//        
//        srcScrollView.setContentOffset(CGPointMake(0.0, activeField!.frame.origin.y - kbSize!.height), animated: true)
//    }

    func keyboardOffScreen(notification: NSNotification){
        let contentInsets:UIEdgeInsets = UIEdgeInsetsZero

        srcScrollView.contentInset = contentInsets
        srcScrollView.scrollIndicatorInsets = contentInsets

        self.srcScrollView.setContentOffset(CGPointMake(0, -self.view.frame.origin.y/2), animated: true)
    }

}

Answer 2

Swift 4.2 qui prend en compte les hauteurs possibles de UIToolbar et UITabBar.

private func setupKeyboardNotifications() {
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(_:)), name: UIControl.keyboardWillShowNotification, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(_:)), name: UIControl.keyboardWillHideNotification, object: nil)
}

@objc func keyboardWillShow(_ notification: Notification) {
    let userInfo: NSDictionary = notification.userInfo! as NSDictionary
    let keyboardSize = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as! NSValue).cgRectValue.size

    let tabbarHeight = tabBarController?.tabBar.frame.size.height ?? 0
    let toolbarHeight = navigationController?.toolbar.frame.size.height ?? 0
    let bottomInset = keyboardSize.height - tabbarHeight - toolbarHeight

    scrollView.contentInset.bottom = bottomInset
    scrollView.scrollIndicatorInsets.bottom = bottomInset
}

@objc func keyboardWillHide(_ notification: Notification) {
    scrollView.contentInset = .zero
    scrollView.scrollIndicatorInsets = .zero
}

Et, si vous ciblez < iOS 9, vous devez désenregistrer l'observateur à un moment donné (merci Joe )

Answer 3

La seule chose que je mettrais à jour dans le code Apple est la méthode keyboardWillBeHidden :, pour assurer une transition en douceur.

// Called when the UIKeyboardWillHideNotification is sent
- (void)keyboardWillBeHidden:(NSNotification*)aNotification
{
    UIEdgeInsets contentInsets = UIEdgeInsetsZero;

    [UIView animateWithDuration:0.4 animations:^{
        self.scrollView.contentInset = contentInsets;
    }];
    self.scrollView.scrollIndicatorInsets = contentInsets;

}

Answer 4

Voici un Swift 3 réponse compatible, cela fonctionnera également avec les contrôleurs de vue au sein d'un contrôleur de navigation, car ils modifieront les vues de défilement. contentInset.top propriété.

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    self.registerKeyboardNotifications()
}

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)

    self.unregisterKeyboardNotifications()
}

func registerKeyboardNotifications() {
    NotificationCenter.default.addObserver(self, selector: #selector(LoginViewController.keyboardDidShow(notification:)), name: NSNotification.Name.UIKeyboardDidShow, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(LoginViewController.keyboardWillHide(notification:)), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}

func unregisterKeyboardNotifications() {
    NotificationCenter.default.removeObserver(self)
}

func keyboardDidShow(notification: NSNotification) {
    let userInfo: NSDictionary = notification.userInfo! as NSDictionary
    let keyboardInfo = userInfo[UIKeyboardFrameBeginUserInfoKey] as! NSValue
    let keyboardSize = keyboardInfo.cgRectValue.size

    // Get the existing contentInset for the scrollView and set the bottom property to be the height of the keyboard
    var contentInset = self.scrollView.contentInset
    contentInset.bottom = keyboardSize.height

    self.scrollView.contentInset = contentInset
    self.scrollView.scrollIndicatorInsets = contentInset
}

func keyboardWillHide(notification: NSNotification) {
    var contentInset = self.scrollView.contentInset
    contentInset.bottom = 0

    self.scrollView.contentInset = contentInset
    self.scrollView.scrollIndicatorInsets = UIEdgeInsets.zero
}

Answer 5

C'est le code final avec des améliorations dans Swift

    //MARK: UITextFieldDelegate
func textFieldDidBeginEditing(textField: UITextField!) {    //delegate method
    self.textField = textField
}

func textFieldShouldReturn(textField: UITextField!) -> Bool {   //delegate method
    textField.resignFirstResponder()
    return true
}

//MARK: Keyboard handling
override func viewWillDisappear(animated: Bool) {
    super.viewWillDisappear(animated)
    unregisterKeyboardNotifications()
}

func registerKeyboardNotifications() {
    NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(UCProfileSettingsViewController.keyboardDidShow(_:)), name: UIKeyboardDidShowNotification, object: nil)
    NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(UCProfileSettingsViewController.keyboardWillHide(_:)), name: UIKeyboardWillHideNotification, object: nil)
}

func unregisterKeyboardNotifications() {
    NSNotificationCenter.defaultCenter().removeObserver(self)
}

func keyboardDidShow(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 = self.view.frame
    viewRect.size.height -= keyboardSize.height
    let relativeFieldFrame: CGRect = textField.convertRect(textField.frame, toView: self.view)
    if CGRectContainsPoint(viewRect, relativeFieldFrame.origin) {
        let scrollPoint = CGPointMake(0, relativeFieldFrame.origin.y - keyboardSize.height)
        scrollView.setContentOffset(scrollPoint, animated: true)
    }

}

func keyboardWillHide(notification: NSNotification) {
    scrollView.contentInset = UIEdgeInsetsZero
    scrollView.scrollIndicatorInsets = UIEdgeInsetsZero
}