I have two labels (CountryCode, CountryName) in prototype cells, and I created a class for them called " CountryCell " and I created the TableViewController class called " CountriesVC " I made the labels' outlets in the CountryCell but I want to use them in CountriesVC and when I do so it reports an error that says 'CountriesVC' Does not have a member named 'CountryCode' .
Thanks a lot.
Here is the code where I want to use CountryCode and CountryName
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "ChangeCountryCode" {
SelectedCCode = self.CountryCode.text
SelectedCName = self.CountryName.text
}
}
Here is CountryCell code :
class CountryCell: UITableViewCell {
#IBOutlet weak var CountryCode: UILabel!
#IBOutlet weak var CountryName: UILabel!
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
}
override func setSelected(selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
}
These properties that you are trying to access are not declared in the current class. You must first create a variable of type "CountryCell" and then access the properties of that class.
Related
I am trying to pass a struct between view controllers, but I get the compiler error "#IBOutlet property cannot have non-object type". I have tried to add #objc but still get the error. How can I pass this data between view controllers? Why do I get this error and how do I correct it? Thanks.
import UIKit
struct DocObject: Codable {
let filename: String
let doclink: Int
}
class ViewController: UIViewController {
#IBOutlet weak var textField: UITextField!
// var nameText = ""
var obj = DocObject(filename: "filename", doclink: 123)
override func viewDidLoad() {
super.viewDidLoad()
}
#IBAction func done(_ sender: Any) {
print ("In VC1 nameText ", obj)
performSegue(withIdentifier: "name", sender: self)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let vc = segue.destination as! VCTwo2
vc.finalObj = obj
}
}
import UIKit
class VCTwo2: UIViewController {
#IBOutlet var finalObj: DocObject!
// var finalName = 0
override func viewDidLoad() {
super.viewDidLoad()
print ("In VC2 ", finalObj!)
}
}
You only define a property with #IBoutlet if the property is loaded from a xib or storyboard. Since you are passing the data structure from another view controller just define finalObj as a regular var.
class VCTwo2: UIViewController {
var finalObj: DocObject!
override func viewDidLoad() {
super.viewDidLoad()
}
}
I'm developing a simple game (my first iOS app!) and am trying to link a variable between two View Controllers. In the first view controller, I have a textfield where the user can type in any number they choose. In the second View Controller, I would like users to be able to generate any number between 1 and the number they entered by pressing a button and be able to keep doing so. However, I am not able to use the "upperBound" variable holding the user-entered value in ViewController2.
I've tried using prepare for segue but it's not working, and I've snooped around stackoverflow and tried a couple of methods without quite knowing what I'm doing to no avail.
(UPDATED) ViewController:
class ViewController: UIViewController, UITextFieldDelegate {
//MARK: Properties
#IBOutlet weak var numberOfPages: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
// Handle the text field’s user input through delegate callbacks.
numberOfPages.delegate = self
}
//MARK: UITextFieldDelegate
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
// Hide the keyboard.
textField.resignFirstResponder()
return true
}
func textFieldDidEndEditing(_ textField: UITextField) {
//Save number entered and then randomly select a number within bounds
}
//MARK: Actions
var upperBound: Int?
#IBAction func setUpperBound(_ sender: UIButton) {
upperBound = Int(numberOfPages.text!)
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!) {
// Create a variable that you want to send
var newUpperBound = Int(upperBound!)
// Create a new variable to store the instance of ViewController2
let destinationVC = segue.destination as! ViewController2
destinationVC.upperBound = newUpperBound
}
}
(UPDATED) ViewController2:
class ViewController2: UIViewController, UITextFieldDelegate {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
/*
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
// Get the new view controller using segue.destination.
// Pass the selected object to the new view controller.
}
*/
//Mark: Actions
#IBAction func roller(_ sender: UIButton) {
//Generate random number
let randomNumber = Int.random(in: 0 ..< upperBound)
}
var upperBound: Int?
}
With this code, I'm getting an error on line 34 of ViewController2 that reads "Use of unresolved identifier upperBound". Additionally, there is an issue on line 40 of ViewController that reads "immutable value upperBound was never used". I would expect to be able to generate a random value between 1 and the entered number so that I can keep working and add more features to my app (like printing these random values etc)
ViewController
import UIKit
class ViewController: UIViewController, UITextFieldDelegate {
#IBOutlet weak var numberOfPages: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
numberOfPages.delegate = self
}
//MARK: UITextFieldDelegate
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
// Hide the keyboard.
textField.resignFirstResponder()
return true
}
func textFieldDidEndEditing(_ textField: UITextField) {
//Save number entered and then randomly select a number within bounds
}
//MARK: Actions
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if numberOfPages.text == ""{
print("Please enter number")
return
}
let upperBound: Int? = Int(numberOfPages.text ?? "0")
if upperBound != 0{
if segue.identifier == "mySegue"{
let vc = segue.destination as! ViewController2
vc.upperBound = upperBound
}
}
}
}
ViewController2
import UIKit
class ViewController2: UIViewController {
#IBOutlet weak var lbl_UpperBound: UILabel!
#IBOutlet weak var btn_Generate: UIButton!
#IBOutlet weak var lbl_Random: UILabel!
var upperBound: Int?
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
lbl_UpperBound.text = "Upper Bound - \(upperBound ?? 0)"
btn_Generate.addTarget(self, action: #selector(roller), for: .touchUpInside)
lbl_Random.text = ""
}
#objc func roller(_ sender: UIButton) {
//Generate random number
let randomNumber = Int.random(in: 0 ..< (upperBound ?? 1))
lbl_Random.text = "\(randomNumber)"
}
}
Also Don't forget to name the Segue
I'm trying to create the feature where when a user clicks on a specific cell in my UITableView, the Project will segue to a new ViewController and show all the information that has been saved in the CoreData. The Problem is that when I touch on a cell I get an error of
Unexpected nil while unwrapping optional value
Here is my code as it is right now within the ViewController that has the TableView
class ContactViewController: UIViewController, UITableViewDataSource, NSFetchedResultsControllerDelegate, UITableViewDelegate {
var selectName:String?
var selectPhone:String?
var selectComment:String?
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
selectName = contact[indexPath.row].name
selectPhone = contact[indexPath.row].phone
selectComment = contact[indexPath.row].comments
performSegue(withIdentifier: "MySegue", sender: self)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "MySegue"{
if let destVC = segue.destination as? IndiViewController {
destVC.NameLabel = selectName
destVC.PhoneLabel = selectPhone
destVC.CommentLabel = selectComment
}
}
}
This is my code in IndiViewController (the VC in which I want the user to view the contact)
class IndiViewController: UIViewController {
#IBOutlet var NameLabel: UILabel!
#IBOutlet var PhoneLabel: UILabel!
#IBOutlet var CommentsLabel: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
}
}
I've tried a few other methods but all still delivered the same error
I troubleshooted a bit to see which variable truly was causing the nil by doing this:
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "MySegue"{
if let destVC = segue.destination as? IndiViewController {
destVC.NameLabel = "selectName" //I thought if perhaps the nil was the var selectName this would at least let me know
}
}
However even through this, the app crashes and gives the same error. So I think the issue is with the Labels in the IndiViewController.
So I tried creating an empty String and assigning it to NameLabel like this:
class IndiViewController: UIViewController {
#IBOutlet var NameLabel: UILabel!
var name = ""
override func viewDidLoad() {
super.viewDidLoad()
NameLabel.text = name
}
}
but still no luck.
What am I doing wrong?
Yet it can be an IBOutlet error, even for typo.
delete #IBOutlet var NameLabel: UILabel!
remove the link in the StoryBoard "referencing outlets" tab
click-drag a new outlet for the UILabel and do not name it with a capital letter
// #IBOutlet var NameLabel: UILabel!
#IBOutlet var nameLabel: UILabel!
Edit
Also try to pass your informations in two times :
create a new var in your destinationViewController like :
class IndiViewController: UIViewController {
#IBOutlet var nameLabel: UILabel!
var myText: String = ""
override func viewDidLoad() {
super.viewDidLoad()
nameLabel.text = myText // assign the var to the labels text
}
}
In your prepareForSegue method assign myText and not the nameLabel.text
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "MySegue"{
if let destVC = segue.destination as? IndiViewController {
destVC.myText = "selectName"
}
}
}
my guess is that you cant acces IBOutlets in prepare(for segue:) method. The destination ViewController is not built yet
View controller A
class ViewController: UIViewController {
var delegate: server?
override func viewDidLoad() {
super.viewDidLoad()
}
#IBAction func ok(_ sender: Any) {
delegate?.datum(data: "sd")
performSegue(withIdentifier: "goingB", sender: self)
}
}
View controller B
protocol server {
func datum(data: String)
}
class ViewControllerB: UIViewController, server {
#IBOutlet weak var label: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
}
func datum(data: String) {
self.label.text = data
print(data)
}
}
I need to pass the data via view controllers but I cannot able to pass however I know we can pass data through protocols, but anyhow I end up with error when try to run the program
If you need to pass data from one view controller to another and you're using segue for presenting new view controller, you can just override prepare(for:sender:), there is no need to using delegates. Here you can get reference for controller which will be presented and you can assign its variable.
So, first create variable in second view controller and declare that if you assign it with new value, it changes text of your label
class ViewControllerB: UIViewController {
#IBOutlet weak var label: UILabel!
var variable: String? {
didSet {
label.text = variable
}
}
}
Now in first view controller override prepare(for:sender:) and if segue is segue which you've performed, downcast destination view controller and assign its variable
class ViewController: UIViewController {
#IBAction func ok(_ sender: Any) {
performSegue(withIdentifier: "goingB", sender: self)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "goingB" {
let destinationVC = segue.destination as! ViewControllerB
destinationVC.variable = "sd"
}
}
}
Anyway, if you want to use your code with delegate, you have to set delegate of first view controller as second view controller which will be presented. For this purpose you can also use prepare(for:sender:) where you can get reference for destination of segue and then you can call your method on delegate
class ViewController: UIViewController {
var delegate: server?
#IBAction func ok(_ sender: Any) {
performSegue(withIdentifier: "goingB", sender: self)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "goingB" {
let destinationVC = segue.destination as! ViewControllerB
delegate = destinationVC
delegate?.datum(data: "sd")
}
}
}
Notes:
Name protocol with big capital letter Server and we are talking about delegates, add delegate word: ServerDelegate
Constrain protocol for just for classes
Make then your delegate variable weak
protocol ServerDelegate: class {
func datum(data: String)
}
...
weak var delegate: ServerDelegate?
The simplest here is to to set the property directly in prepare.
However, if you want to use delegate, you can. Your problem is that you have mixed between A and B.
The way you wrote it, when you call delegate?.datum, delegate is not defined and we can't access datum.
What do you want to do ? Go from A to B, and when in B, update a label in B with data received from A.
Here just to show how to use (but clearly too complex compared with direct assignment).
protocol Server {
func datum() -> String
}
class ViewControllerB: UIViewController {
#IBOutlet weak var label: UILabel!
var delegate: Server?
override func viewDidLoad() {
super.viewDidLoad()
let data = delegate?.datum()
self.label.text = data
}
}
class ViewControllerA: UIViewController, Server {
override func viewDidLoad() {
super.viewDidLoad()
}
var data = "sd"
func datum() -> String {
return data
}
#IBAction func ok(_ sender: Any) {
performSegue(withIdentifier: "goingB", sender: self)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if let destVC = segue.destination as? ViewControllerB {
destVC.delegate = self
}
}
}
My custom cell has a button that when clicked, the user can be taken to another ViewControler. That button has a titleLabel with the String of a user id. What I want to do is take the user to a new UIViewController, passing that clicked buttons's titleLabel (user id) to a variable on the new View Controller. That way, I can use that variable (user id) get further information from firebase and display it on the UI View controller.
on the .xib of the custom cell, I print the UID to make sure each button prints with the correspondent ID, which it does. I can't figure out a way to pass that ID to a new ViewController.
I tried researching online and I found out you can't do prepare(for segue) or performsegue(WithIdentifier) on a customCell.xib.
I tried doing delegates and then protocols but still couldn't get it to work. I am new with Swift. Any help would be great, thank you!
This is the customCell.Xib's Swift file:
class CustomCellTableViewCell: UITableViewCell {
#IBOutlet weak var postImage: UIImageView!
#IBOutlet weak var nameLbl: UILabel!
#IBOutlet weak var descriptionLbl: UITextView!
#IBOutlet weak var profileImageBtn: UIButton!
#IBOutlet weak var profileImage: UIImageView!
#IBOutlet weak var view: UIView!
var btnSelected : Bool = false
var vcInstance: ProfilesTableVC?
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
view.clipsToBounds = true
view.layer.cornerRadius = view.frame.size.width / 2
profileImage.layer.cornerRadius = profileImage.frame.size.width / 2
descriptionLbl.alpha = 0.7
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
}
#IBAction func profileBtnPressed(_ sender: Any) {
let passValue = UserProfileVC()
let profileTvC = ProfilesTableVC()
print (profileImageBtn.titleLabel!.text!)
var id = (profileImageBtn.titleLabel!.text!)
profileTvC.didSelectProfileBtn(senderID: id)
}
This is the tableViewController, where I everything gets loaded (not where I want to pass the value). I tried passing the value here and then do a prepareForSegue to pass the value to the new UIViewController but the value becomes nil after the segue happens. I am just including code where the .xib call the function from the table view.
class ProfilesTableVC: UIViewController, UITableViewDelegate, UITableViewDataSource, UITextFieldDelegate,UINavigationControllerDelegate, UIImagePickerControllerDelegate{
let cell = CustomCellTableViewCell()
func didSelectProfileBtn(senderID: String) {
senderIDArray.append(senderID)
var index = senderIDArray.count - 1
selectedCellUserID = senderIDArray[index]
performSegue(withIdentifier: "showSendersProfile", sender: Any?.self)
}
This is the UIViewController where I want to pass the variable and display further information from Firebase using that ID
import UIKit
import Firebase
class UserProfileVC: UIViewController {
let customCell = CustomCellTableViewCell()
let profileTvC = ProfilesTableVC()
#IBOutlet weak var profileImage: UIImageView!
#IBOutlet weak var nameLbl: UILabel!
var delegate : Any?
var getName = String()
var getsenderID = String()
let userDataRef = Database.database().reference().child("Users")
override func viewDidLoad() {
super.viewDidLoad()
print("ID is: \(profileTvC.selectedCellUserID)")
let sender = getsenderID
print(sender)
}
}
If you don't want to use protocols, you can addTarget to the button in the tableView - cellForRowAt method, also in that method you set the tag to the row index value.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let profileCell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier) as! MoviewReviewCell
reviewCell.profileImageBtn.tag = indexPath.row
reviewCell.profileImageBtn.addTarget(self, action: #selector(tappedOnXibCellButton), for: .touchUpInside)
return reviewCell
}
#objc func tappedOnXibCellButton(sender: UIButton) {
print(sender.tag)
performSegue(withIdentifier: reviewListToDetails, sender: sender.tag)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let identifier = segue.identifier
if identifier == "segueName" {
let destViewController = segue.destination as! DestinationClassViewController
let selectedIndex = sender as! Int
let profileId = profilesList[selectedIndex].id
destViewController.profileId = profileId
}
}
You seem to create a NEW ProfilesTableVC, and try to perform the segue on. The newly created one is not on your view stack, and not from your storyboard.
You could add this while returned cellForRowAt (at the ProfilesTableVC of course):
cell.vcInstance = self
Then in the button click
#IBAction func profileBtnPressed(_ sender: Any) {
print (profileImageBtn.titleLabel!.text!)
var id = (profileImageBtn.titleLabel!.text!)
vcInstance?.didSelectProfileBtn(senderID: id)
}
You can do it with protocols/delegates. I think you tried but there is something wrong with your trial.
Define a callback delegate:
protocol CustomCellDelegate: AnyObject {
func customCell(didSelectButton name: String)
}
You will notice extending AnyObject. This is to allow weak references, try to read about Swift ARC
Then, in your cell:
weak var delegate: CustomCellDelegate?
Then in the profileBtnPressed(_ sender: Any)
#IBAction func profileBtnPressed(_ sender: Any) {
var id = (profileImageBtn.titleLabel!.text!)
delegate?.customCell(didSelectButton: id)
}
When dequeing the cell:
(cell as? CustomCellTableViewCell)?.delegate = self