UITextField move up when keyboard appears in Swift

问题:

I use this code for move the view up when keyboard appears, in my login page this code worked great, but in the signup page it did not work.

func textFieldDidBeginEditing(textField: UITextField) {
    animateViewMoving(true, moveValue: 100)
}
func textFieldDidEndEditing(textField: UITextField) {
    animateViewMoving(false, moveValue: 100)
}

func animateViewMoving (up:Bool, moveValue :CGFloat){
    var movementDuration:NSTimeInterval = 0.3
    var movement:CGFloat = ( up ? -moveValue : moveValue)
    UIView.beginAnimations( "animateView", context: nil)
    UIView.setAnimationBeginsFromCurrentState(true)
    UIView.setAnimationDuration(movementDuration )
    self.view.frame = CGRectOffset(self.view.frame, 0,  movement)
    UIView.commitAnimations()
}

I have another function to return key on the keyboard, it also worked on the login page but not on the signup page. All things are same between the two pages.

  func textFieldShouldReturn(textField: UITextField) -> Bool {

    textField.resignFirstResponder()
    return true
}

回答1:

have you assigned your delegate of UITextField in your ViewController class? if not set it to self.

self.youttextfield.delegate = self

回答2:

Demo link : https://github.com/harshilkotecha/UIScrollViewWhenKeyboardAppearInSwift3

when you have multiple textview it is so difficult so best solution ->

step 1 : add UITextFieldDelegate

class ScrollViewController: UIViewController,UITextFieldDelegate {

step 2 :create new IBOutlet but don't connect with any text field

//  get current text box when user Begin editing
    @IBOutlet weak var activeTextField: UITextField?

step 3 : write this two method when user focus on text filed object pass the reference and store in activeTextField

// get current text field
    func textFieldDidBeginEditing(_ textField: UITextField)
    {
        activeTextField=textField;
    }
    func textFieldDidEndEditing(_ textField: UITextField)
    {
        activeTextField=nil;
    }

step 5 : set Notification in viewdidload setNotificationKeyboard

 override func viewWillAppear(_ animated: Bool) {
            // call method for keyboard notification
            self.setNotificationKeyboard()
        }

        // Notification when keyboard show
        func setNotificationKeyboard ()  {
            NotificationCenter.default.addObserver(self, selector: #selector(keyboardWasShown(notification:)), name: .UIKeyboardWillShow, object: nil)
            NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillBeHidden(notification:)), name: .UIKeyboardWillHide, object: nil)
        }

step 6 : two method for hide and unhide

func keyboardWasShown(notification: NSNotification)
    {
        var info = notification.userInfo!
        let keyboardSize = (info[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue.size
        let contentInsets : UIEdgeInsets = UIEdgeInsetsMake(0.0, 0.0, keyboardSize!.height+10, 0.0)
        self.scrollView.contentInset = contentInsets
        self.scrollView.scrollIndicatorInsets = contentInsets
        var aRect : CGRect = self.view.frame
        aRect.size.height -= keyboardSize!.height
        if let activeField = self.activeTextField
        {
            if (!aRect.contains(activeField.frame.origin))
            {
                self.scrollView.scrollRectToVisible(activeField.frame, animated: true)
            }
        }
    }
// when keyboard hide reduce height of scroll view


 func keyboardWillBeHidden(notification: NSNotification){
        let contentInsets : UIEdgeInsets = UIEdgeInsetsMake(0.0, 0.0,0.0, 0.0)
        self.scrollView.contentInset = contentInsets
        self.scrollView.scrollIndicatorInsets = contentInsets
        self.view.endEditing(true)
    }