move UITextField up when keyboard present - swift

Question

I have recently started to develop my own app following the instructions on internet. I am just a beginner (with no knowledge of coding) and hence may be doing very stupid mistake that I am not able to catch.
In my app I am facing a situation where my email text field is hiding behind the keyboard whenever I try to type email address. I did some research (on stack overflow) and wrote a piece of code that suppose to move my text field up but it is not ... I believe overall structure of code is right (I may be wrong here though) but it may be just tiny mistake that making my code ineffective.
can anyone guide me on what I am doing wrong here?
below is the piece of code I wrote:
{
import UIKit
import WebKit
import CoreGraphics
import AVFoundation
import QuartzCore
import Foundation
class StudentSignUpViewController: UIViewController,UIScrollViewDelegate, UITextFieldDelegate {
#IBOutlet weak var yourEmail: UITextField!
#IBOutlet weak var scrollView: UIScrollView!
override func viewDidLoad() {
super.viewDidLoad()
//setting portrait
AppUtility.lockOrientation(.portrait)
//hide keyboard when click outside
self.hideKeyboardWhenTappedAround()
//hide keyboard when click on return
self.yourEmail.delegate = self
self.scrollView.delegate = self
//boarder line for yourEmail
yourEmail.frame.size.height = UIScreen.main.fixedCoordinateSpace.bounds.size.width * CGFloat(0.05)
yourEmail.font = UIFont.italicSystemFont(ofSize: UIScreen.main.fixedCoordinateSpace.bounds.size.width * CGFloat(0.04))
bottomBoader(BottomLine: "UrEmailTextBottomLine", length: 1.0, yourTextBox: yourEmail)
yourEmail.applyCustomClearButton(yourTextBox: yourEmail)
registerForKeyboardNotifications()
deregisterFromKeyboardNotifications()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
AppUtility.lockOrientation(.portrait)
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
AppUtility.lockOrientation(.all)
}
// *************************************************** moving textfiles when keyborad present ***********************************************************
func registerForKeyboardNotifications(){
//Adding notifies on keyboard appearing
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWasShown(notification:)), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillBeHidden(notification:)), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}
func deregisterFromKeyboardNotifications(){
//Removing notifies on keyboard appearing
NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}
#objc func keyboardWasShown(notification: NSNotification){
//Need to calculate keyboard exact size due to Apple suggestions
self.scrollView.isScrollEnabled = true
var info = notification.userInfo!
let keyboardSize = (info[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue.size
let contentInsets : UIEdgeInsets = UIEdgeInsetsMake(0.0, 0.0, keyboardSize!.height, 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.yourEmail {
if (!aRect.contains(activeField.frame.origin)){
self.scrollView.scrollRectToVisible(activeField.frame, animated: true)
}
}
}
#objc func keyboardWillBeHidden(notification: NSNotification){
//Once keyboard disappears, restore original positions
var info = notification.userInfo!
let keyboardSize = (info[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue.size
let contentInsets : UIEdgeInsets = UIEdgeInsetsMake(0.0, 0.0, -keyboardSize!.height, 0.0)
self.scrollView.contentInset = contentInsets
self.scrollView.scrollIndicatorInsets = contentInsets
self.view.endEditing(true)
self.scrollView.isScrollEnabled = false
//self.scrollView.contentInset = UIEdgeInsets.zero
}
func textFieldDidBeginEditing( textField: UITextField){
yourEmail = textField
}
func textFieldDidEndEditing(textField: UITextField){
yourEmail = nil
}

Answer 1

The problem is you are registerForKeyboardNotifications() and then immediately deregisterFromKeyboardNotifications() so you aren't getting keyboard notifications. You should move the deregister to the deinit:
deinit {
deregisterFromKeyboardNotifications()
}
Edit
As #matt pointed out you don't need to deregisterFromKeyboardNotifications so just delete that code (including my suggestion of deinit)

Answer 2

Embedding your controls in a UITableView with static cells on a Storyboard will let the system take care of the scrolling for you.

Answer 3

hey bro why are call both the functions in viewDidLoad
registerForKeyboardNotifications()
deregisterFromKeyboardNotifications()
In viewDidLoad call only registerForKeyboardNotifications() and in deinit call deregisterFromKeyboardNotifications()

Answer 4

final solution that is working fine, I have copied it from stack overflow and tweak it little bit for my purpose:
var activeField: UITextField?
func registerForKeyboardNotifications(){
//Adding notifies on keyboard appearing
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWasShown(notification:)), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillBeHidden(notification:)), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}
#objc func keyboardWasShown(notification: NSNotification){
//Need to calculate keyboard exact size due to Apple suggestions
self.scrollView.isScrollEnabled = true
var info = notification.userInfo!
let keyboardSize = (info[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue.size
let contentInsets : UIEdgeInsets = UIEdgeInsetsMake(0.0, 0.0, keyboardSize!.height, 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.activeField {
if activeField.frame.maxY > (scrollView.frame.height - keyboardSize!.height){
self.scrollView.setContentOffset(CGPoint.init(x: 0, y: activeField.frame.maxY - (scrollView.frame.height - keyboardSize!.height) + 20), animated: true)
} else {
return
}
print(activeField.frame.maxY)
print(scrollView.frame.height)
print(keyboardSize!.height)
print(scrollView.frame.height - keyboardSize!.height)
print(activeField.frame.maxY - (scrollView.frame.height - keyboardSize!.height) + 20)
}
}
#objc func keyboardWillBeHidden(notification: NSNotification){
//Once keyboard disappears, restore original positions
var info = notification.userInfo!
let keyboardSize = (info[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue.size
let contentInsets : UIEdgeInsets = UIEdgeInsetsMake(0.0, 0.0, -keyboardSize!.height, 0.0)
self.scrollView.contentInset = contentInsets
self.scrollView.scrollIndicatorInsets = contentInsets
self.view.endEditing(true)
self.scrollView.isScrollEnabled = false
}
func textFieldDidBeginEditing(_ textField: UITextField){
activeField = textField
}
func textFieldDidEndEditing(_ textField: UITextField){
activeField = nil
}