I am trying to use segues to pass the data entered in the partyID text field to the partyID label in a separate view controller. However, I am getting errors in my code.
class PartyViewController: UIViewController {
// CALLS LOGIN VC
var LoginViewController: LoginViewController?
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
#IBOutlet weak var partyID: UITextField!
var token = String()
#IBAction func startParty(_ sender: UIButton) {
self.performSegue(withIdentifier: "partyVCtoGuestPartyVC", sender: self)
performSegue(withIdentifier: "hostStartParty", sender: self)
//LoginViewController?.fetchSpotifyProfile(accessToken )
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if(segue.identifier == "partyVCtoGuestPartyVC"){
let GuestPartyVC = segue.destination as! GuestPartyViewController
GuestPartyVC.partyID = partyID.text
}
And here is the view controller I am trying to pass the data to:
class GuestPartyViewController: UIViewController {
#IBOutlet weak var partyID: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
partyIDLabel.text = partyID
// Do any additional setup after loading the view.
}
I get errors in my override func in LoginVC and then in the partyIDlabel.text in the GuestPartyVC.
In GuestPartyViewController
class GuestPartyViewController: UIViewController {
#IBOutlet weak var partyIDLabel: UILabel!
var partyID: String?
override func viewDidLoad() {
super.viewDidLoad()
partyIDLabel.text = partyID ?? ""
}
}
In PartyViewController
class PartyViewController: UIViewController {
#IBOutlet weak var partyID: UITextField!
#IBAction func startParty(_ sender: UIButton) {
self.performSegue(withIdentifier: "partyVCtoGuestPartyVC", sender: self)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "partyVCtoGuestPartyVC",
let GuestPartyVC = segue.destination as? GuestPartyViewController {
GuestPartyVC.partyID = partyID.text
}
}
}
The IBOutlet is weak and may not be instantiate when you pass the text.
Could you try to pass the text in a property, then assign it in the viewDidLoad ?
class GuestPartyViewController: UIViewController {
#IBOutlet weak var partyID: UILabel!
var passedText: String?
override func viewDidLoad() {
super.viewDidLoad()
if let unwrappedPassedText = passedText {
partyIDLabel.text = partyID
}
}
// In the other controller
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if(segue.identifier == "partyVCtoGuestPartyVC") {
let GuestPartyVC = segue.destination as! GuestPartyViewController
GuestPartyVC.passedText = partyID.text
}
first change the call of login VC
var LoginViewController = LoginViewController()
then put this before the view did load method
#IBOutlet weak var partyID: UITextField!
and can you send the error that you get
Related
how do you pass data from search Bar to UILabel in a different view controller
Passing Data between View Controllers
I have tried multiple questions here on stack, but it just doesn't work or the simulator ends up crashing for me
class FirstVC: UIViewController, DataEnteredDelegate {
#IBOutlet weak var label: UILabel!
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "showSecondViewController" {
let secondViewController = segue.destination as! SecondVC
secondViewController.delegate = self
}
}
func userDidEnterInformation(info: String) {
label.text = info
}
}
// protocol used for sending data back
protocol DataEnteredDelegate: class {
func userDidEnterInformation(info: String)
}
class SecondVC: UIViewController {
// making this a weak variable so that it won't create a strong reference cycle
weak var delegate: DataEnteredDelegate? = nil
#IBOutlet weak var searchBar: UISearchBar!
#IBAction func sendTextBackButton(sender: AnyObject) {
// call this method on whichever class implements our delegate protocol
delegate?.userDidEnterInformation(info: searchBar.text!)
// go back to the previous view controller
_ = self.navigationController?.popViewController(animated: true)
}
}
I don't find anything suspicious in your code which cause app crash. Meanwhile for data transfer between view controller we can use delegation and NotificationCenter. Below code uses NotificationCenter
let kStringTransfer = "StringTransferNotification"
class FirstViewController: UIViewController, DataEnteredDelegate {
#IBOutlet weak var textField: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
NotificationCenter.default.addObserver(self, selector: #selector(setString(notify:)), name: NSNotification.Name(rawValue: kStringTransfer), object: nil)
}
func getSecondVC() {
if let second = self.storyboard?.instantiateViewController(withIdentifier: "Second") as? ViewController {
self.navigationController?.pushViewController(second, animated: true)
}
}
#IBAction func searchBarBtn(_ sender: Any) {
//go to search view controller
getSecondVC()
}
#objc func setString(notify: Notification) {
//set search bar string to text field
textField.text = notify.object as? String
}
}
class SecondViewController: UIViewController, UISearchBarDelegate {
#IBOutlet weak var searchBar: UISearchBar!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
searchBar.delegate = self
}
#IBAction func goBackBtn(_ sender: Any) {
NotificationCenter.default.post(name: NSNotification.Name(rawValue: kStringTransfer), object: searchBar.text)
self.navigationController?.popViewController(animated: true)
}
}
When I need pass just small values between 2 viewControllers, I don't use a delegate, just create a variable in second view and pass like this.
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if (segue.identifier == "showView") {
let vc = segue.destination as! secondViewController
vc.stringTemp = "My string"
}
}
I am new to Swift and was wondering on how to pass data from ViewController to ViewController that isn’t connected by segue. I have spend 2 hours on this and still can’t figure a way to do it.
Edit: The problem that I am confused on is How to take out all the stacked ViewController expect the root ViewController while being able to pass data back to the first ViewController from ViewController3 with
'navigationController?.popToRootViewController(animated: false)'
class ViewController: UIViewController, nameDelegate {
#IBOutlet weak var label1: UILabel!
#IBOutlet weak var textfield1: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
label1.text = "Name"
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let vc2 = segue.destination as! ViewController2
vc2.middleOfTransferingName = textfield1.text!
}
#IBAction func buttonPressed1(_ sender: Any) {
performSegue(withIdentifier: "go2", sender: self)
}
func nameThatWasEntered(name: String) {
label1.text = name
}
}
class ViewController2: UIViewController, nameDelegate {
var middleOfTransferingName: String = ""
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let vc3 = segue.destination as! ViewController3
vc3.transferedWithSegueLabelText = middleOfTransferingName
vc3.namePassBack = self
}
#IBAction func buttonPressed2(_ sender: Any) {
performSegue(withIdentifier: "go3", sender: self)
}
func nameThatWasEntered(name: String) {
}
}
protocol nameDelegate {
func nameThatWasEntered(name: String)
}
class ViewController3: UIViewController {
#IBOutlet weak var label3: UILabel!
#IBOutlet weak var textfield3: UITextField!
var transferedWithSegueLabelText: String = ""
var namePassBack: nameDelegate?
override func viewDidLoad() {
super.viewDidLoad()
label3.text = transferedWithSegueLabelText
}
#IBAction func buttonPressed3(_ sender: Any) {
namePassBack!.nameThatWasEntered(name: textfield3.text!)
navigationController?.popToRootViewController(animated: false)
}
}
I found the way to transfer ViewController3 data to ViewController!
var vc3 = ViewController3()
then making ViewController as the delegate of vc3 upon loading.
override func viewDidLoad() {
super.viewDidLoad()
vc3.namePassBack = self
}
Then going back to ViewController3, I add ""vc3."" before using the delegate.
#IBAction func buttonPressed3(_ sender: Any) {
vc3.namePassBack!.nameThatWasEntered(name: textfield3.text!)
navigationController?.popToRootViewController(animated: false)
}
if you use segue then use 'Unwind segue'
for this write given code in your 'A view controller'
#IBAction func unwindToThisViewController(segue: UIStoryboardSegue) {
}
In B_viewcontroller, On press button call 'Unwind segue'.
Note:- With the help of Unwind segue you can send the value for 3ed vc to 1se vc same as you send value form 1st vc to 2nd vc
for more go to this link
I have this code:
MainViewControler:
class MainViewControler: UIViewController, ContainerToMaster {
#IBOutlet weak var systemContainerView: UIView!
#IBOutlet weak var favoriteProductBtn2: UIButton!
weak var containerViewController: Calculator1ViewController?
func changeBtn() {
favoriteProductBtn2.isHidden = true
print("XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX")
}
}
CallculatorViewController:
#IBOutlet weak var containerView: UIView!
class CallculatorViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
}
}
Calculator1ViewController:
protocol ContainerToMaster {
func changeBtn()
}
class Calculator1ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
containerToMaster?.changeBtn()
}
}
I have such an application layout:
Main view = MainViewControler.
In MainViewControler, I have a containerView (systemContainerView) in which the MainViewControler is located
In the CallculatorViewController, I have the next containerView in which the Calculator1ViewController is located.
When entering the Calculator1ViewController the function: containerToMaster?.changeBtn() should start (it should work in MainViewControler).
The problem is - this function does not work :(
Does anyone know how to fix it?
A contained viewController is embedded with an embed segue. You need to override prepare(for:sender) and set self as the containerToMaster delegate in the destination viewController. Your situation is complicated by the fact that you have a container view embedded in another container view, so you'll need to set up two delegates and pass the button call back:
protocol ContainerToMaster {
func changeBtn()
}
class MainViewControler: UIViewController, ContainerToMaster {
#IBOutlet weak var systemContainerView: UIView!
#IBOutlet weak var favoriteProductBtn2: UIButton!
weak var containerViewController: Calculator1ViewController?
func changeBtn() {
favoriteProductBtn2.isHidden = true
print("XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX")
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if let destVC = segue.destination as? CallculatorViewController {
destVC.containerToMaster = self
}
}
}
class CallculatorViewController: UIViewController, ContainerToMaster {
weak var containerToMaster: ContainerToMaster?
override func viewDidLoad() {
super.viewDidLoad()
}
func changeBtn() {
// pass the button call back
containerToMaster?.changeBtn()
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if let destVC = segue.destination as? Calculator1ViewController {
destVC.containerToMaster = self
}
}
}
class Calculator1ViewController: UIViewController {
weak var containerToMaster: ContainerToMaster?
override func viewDidLoad() {
super.viewDidLoad()
containerToMaster?.changeBtn()
}
}
Please, before you mark this question as duplicate, I want to know why my code is failing, not to be send to another one that is working.
I am a newbie in swift and I would like to send a variable "um_words" (which is calculated when a button is clicked) from a viewController when the same button is clicked, save that variable in the secondViewController and show it in a textView. To do so I have tried with many modifications of this code, which is giving no errors in the console but not showing the value of the variable on the textView:
1st VC
import UIKit
import Foundation
class TransViewController: UIViewController {
#IBOutlet var trad_text: UITextView!
#IBOutlet var buttonTrad: UIButton!
#IBOutlet var labelsitoh: UILabel!
var num_words = 0
#IBAction func butCalc(_ sender: UIButton) {
let text = trad_text.text
num_words = (text?.components(separatedBy: " ").count)!-1
func prepare(for segue: UIStoryboardSegue, sender: Any?) {
var DestViewController : PaymentViewController = segue.destination as! PaymentViewController
DestViewController.num_words = String(num_words)
}
}
override func viewDidLoad() {
super.viewDidLoad()
trad_text!.layer.borderWidth = 1
trad_text!.layer.cornerRadius = 20
trad_text!.layer.borderColor = UIColor(red:0.22, green:0.26, blue:0.39, alpha:1.0).cgColor
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
}
2nd VC
import UIKit
import Foundation
class PaymentViewController: UIViewController {
#IBOutlet var labelImport: UITextView!
var num_words = String()
override func viewDidLoad() {
super.viewDidLoad()
labelImport.text = num_words
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
}
I have ab hypothesis of why it is not working: the function "prepare" is not being called; it only goes to next VC when the button is clicked...
Thank you for your time.
The func prepare should be outside of the button action, it will be called when segue is triggered.
#IBAction func butCalc(_ sender: UIButton) {
let text = trad_text.text
num_words = (text?.components(separatedBy: " ").count)!-1
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
var DestViewController : PaymentViewController = segue.destination as! PaymentViewController
DestViewController.num_words = String(num_words)
}
See:
IBAction func butCalc(_ sender: UIButton) {
let text = trad_text.text
num_words = (text?.components(separatedBy: " ").count)!-1
self.performSegue(withIdentifier: "yourSegueIdentifier", sender: self)
}
override func prepareForSegue(segue: UIStoryboardSegue!, sender: AnyObject!) {
if (segue.identifier == "yourSegueIdentifier") {
var destViewController : PaymentViewController = segue.destination as! PaymentViewController
destViewController.num_words = String(num_words)
}
}
You have create a function in another function...
Please try this.
PS: I did not test this code
I want to the image thats in my UIImageView on my previous View after I tap on a button.
Any help? Thanks.
MainViewController.swift
class MainViewController: UIViewController {
#IBOutlet weak var hatBackground: UIImageView!
override func viewDidLoad() {
super.viewDidLoad()
hatBackground.image = UIImage(named: "black-hat-front.jpg")
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "showPatches"{
if let childViewController = segue.destination as? ChildViewController{
}
}
}
}
ChildViewController.swift
class ChildViewController: UIViewController {
#IBOutlet weak var doubleCupButton: UIButton!
override func viewDidLoad() {
super.viewDidLoad()
self.title = "Choose a Patch"
}
#IBAction func doubleCupButtonPressed(_ sender: AnyObject) {
hatBackground.image = UIImage(named: "badgal-hat.jpg")??
// Go back to previous Controller
navigationController?.popViewController(animated: true)
}
}
If I good understood , you want choose image in ChildViewController and show it in MainViewController. To do that you should implement delegate pattern like this:
MainViewController
class MainViewController: UIViewController, ChildViewControllerDelegate {
#IBOutlet weak var hatBackground: UIImageView!
override func viewDidLoad() {
super.viewDidLoad()
hatBackground.image = UIImage(named: "black-hat-front.jpg")
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "showPatches"{
if let childViewController = segue.destination as? ChildViewController{
childViewController.delegate = self
}
}
}
func didSelectImage(image: UIImage?) {
self.hatBackground.image = image
}
}
ChildViewController
class ChildViewController: UIViewController {
#IBOutlet weak var doubleCupButton: UIButton!
var delegate: ChildViewControllerDelegate?
override func viewDidLoad() {
super.viewDidLoad()
self.title = "Choose a Patch"
}
#IBAction func doubleCupButtonPressed(_ sender: AnyObject) {
let selectedImage = UIImage(named: "badgal-hat.jpg")
delegate?.didSelectImage(image: selectedImage)
self.navigationController?.popViewController(animated: true)
}
}
ChildViewControllerDelegate
protocol ChildViewControllerDelegate {
func didSelectImage(image:UIImage?)
}