Scrollview and keyboard Swift

Question

I'm new here and im starting with Swift for iOS.

I started creating a simple app that does some operations. But I'm having some problems when the keyboard appears, hiding one of my textFields. I think it's a common problem and I did some research but I couldn't find anything that solved my problem. And I want to use a Scroll rather than animate the textField to make it visible.

Thanks!!!!! (sorry for english mistakes)

Answer 1

contentInset doesn't work for me, because I want the scrollview move all the way up above the keyboard. So I use contentOffset:

func keyboardWillShow(notification:NSNotification) {
    guard let keyboardFrameValue = notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue else {
        return
    }
    let keyboardFrame = view.convert(keyboardFrameValue.cgRectValue, from: nil)
    scrollView.contentOffset = CGPoint(x:0, y:keyboardFrame.size.height)
}

func keyboardWillHide(notification:NSNotification) {
    scrollView.contentOffset = .zero
}

Answer 2

Here is a complete solution in Swift 4, utilizing guard and concise code. Plus correct code in keyboardWillHide to only reset the bottom to 0.

@IBOutlet weak var scrollView: UIScrollView!

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

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

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

private func unregisterNotifications() {
    NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillShowNotification, object: nil)
    NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillHideNotification, object: nil)
}

@objc func keyboardWillShow(notification: NSNotification){
    guard let keyboardFrame = notification.userInfo![UIResponder.keyboardFrameEndUserInfoKey] as? NSValue else { return }
    scrollView.contentInset.bottom = view.convert(keyboardFrame.cgRectValue, from: nil).size.height
}

@objc func keyboardWillHide(notification: NSNotification){
    scrollView.contentInset.bottom = 0
}

Answer 3

You can animate your scrollview to center on your UITextField on keyboard appearance (ie. making your textfield the first responder) via a scroll offset. Here are a couple of good resources to get you started (there are a bunch on this site):

How programmatically move a UIScrollView to focus in a control above keyboard?

How to make a UIScrollView auto scroll when a UITextField becomes a first responder

Additionally, if you simply use a UITableView with your content in cells, when the textfield becomes first responder, the UITableViewController will automatically scroll to the textfield cell for you (though I'm not sure this is what you want to do).

Answer 4

for Swift 4.0

In ViewDidLoad

// setup keyboard event
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)

Add below observer methods which does the automatic scrolling when keyboard appears.

@objc func keyboardWillShow(notification:NSNotification){
    var userInfo = notification.userInfo!
    var keyboardFrame:CGRect = (userInfo[UIKeyboardFrameBeginUserInfoKey] as! NSValue).cgRectValue
    keyboardFrame = self.view.convert(keyboardFrame, from: nil)

    var contentInset:UIEdgeInsets = self.ui_scrollView.contentInset
    contentInset.bottom = keyboardFrame.size.height
    ui_scrollView.contentInset = contentInset
}

@objc func keyboardWillHide(notification:NSNotification){

    let contentInset:UIEdgeInsets = UIEdgeInsets.zero
    ui_scrollView.contentInset = contentInset
}

Answer 5

Reading the links you sent to me, I found a way to make it work, thanks!:

func textFieldDidBeginEditing(textField: UITextField) {            
    if (textField == //your_field) {
        scrollView.setContentOffset(CGPointMake(0, field_extra.center.y-280), animated: true)
        callAnimation()
        viewDidLayoutSubviews()
    }
}

func textFieldDidEndEditing(textField: UITextField) {    
    if (textField == //your_field){
        scrollView .setContentOffset(CGPointMake(0, 0), animated: true)
        viewDidLayoutSubviews()
    }
}

Answer 6

From the answer by Sudheer Palchuri, converted for Swift 4.

In ViewDidLoad, register the notifications:

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)

And then:

// MARK: - Keyboard Delegates
func textFieldShouldReturn(textField: UITextField) -> Bool {
    textField.resignFirstResponder()
    return true
}

@objc func keyboardWillShow(notification:NSNotification){

    var userInfo = notification.userInfo!
    var keyboardFrame:CGRect = (userInfo[UIKeyboardFrameBeginUserInfoKey] as! NSValue).cgRectValue
    keyboardFrame = self.view.convert(keyboardFrame, from: nil)

    var contentInset:UIEdgeInsets = self.scrollView.contentInset
    contentInset.bottom = keyboardFrame.size.height
    self.scrollView.contentInset = contentInset
}

@objc func keyboardWillHide(notification:NSNotification){

    let contentInset:UIEdgeInsets = UIEdgeInsets.zero
    self.scrollView.contentInset = contentInset
}