Use of unresolved identifier "performSegue" error - ios

Why does Xcode tell me that performSegue(withIdentifier:) is an unresolved identifier? (Please see commented out line)
import UIKit
class AllListsViewController: UITableViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Uncomment the following line to preserve selection between presentations
// self.clearsSelectionOnViewWillAppear = false
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem()
}
// MARK: - Table view data source
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 3
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = makeCell(for: tableView)
cell.textLabel!.text = "List \(indexPath.row)"
return cell
}
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
performSegue(withIdentifier: "ShowChecklist", sender: nil) // Use of unresolved identifier "performSegue"
}
func makeCell(for tableView: UITableView) -> UITableViewCell {
let cellIdentifier = "Cell"
if let cell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier) {
return cell
} else {
return UITableViewCell(style: .default, reuseIdentifier: cellIdentifier)
}
}

You have a two errors in your code:
Line 27 } shall be at the end since this ends the class
You´re inheriting from UITableViewController, so you need to override tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath)
Code that compiles:
import UIKit
class AllListsViewController: UITableViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Uncomment the following line to preserve selection between presentations
// self.clearsSelectionOnViewWillAppear = false
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem()
}
// MARK: - Table view data source
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 3
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = makeCell(for: tableView)
cell.textLabel!.text = "List \(indexPath.row)"
return cell
}
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
performSegue(withIdentifier: "ShowChecklist", sender: nil) // Use of unresolved identifier "performSegue"
}
func makeCell(for tableView: UITableView) -> UITableViewCell {
let cellIdentifier = "Cell"
if let cell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier) {
return cell
} else {
return UITableViewCell(style: .default, reuseIdentifier: cellIdentifier)
}
}
}

Try including UIViewController to the class, that fixed my issue:
class AllListsViewController: UITableViewController, UIViewController {
^^^^^^^^^^^^^^^^

Related

How to show UITableView Cell in UITableView without array?

I have this code:
class UserProfilViewController: UIViewController {
// Outlets
#IBOutlet weak var userProfileTableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
self.tabBarController?.navigationItem.title = "Profil"
}
}
// MARK: - Table View Data Source
extension UserProfilViewController {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 1
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "UserProfilCell", for: indexPath)
return cell
}
}
My project in bitbucket: https://bitbucket.org/trifek/karta-nauka/src/master/
I placed one tableviewcell cell on the tableview (UserProfil.storyboard). I have a form on it that I would like to display in this cell. The problem is the cell does not display. Does anyone know how to fix it?
As per the code you have shared, Please change your code to following.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "UserProfilCell", for: indexPath) as! UserProfilTableViewCell
return cell
}
Let me know in case of any queries.
IMHO, first try to clear your requirements. If you want to display fix number of cells then you can simply use static cells. If your cells are dynamic i.e their number depends on some calculation or other logic, then you can use dynamic cell. While using dynamic cell, verify if you have registered it or not (if you are using xib for cell) and also verify for the cell identifier.
#Lukasz
Please use the below code for this.
class UserProfileViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
setUIComponents()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
private func setUIComponents(){
registerNibs()
}
}
extension UserProfileViewController: UITableViewDelegate, UITableViewDataSource{
internal func registerNibs(){
tableView.register(UINib(nibName: String(describing: UserProfileTableCell.self), bundle: Bundle.main), forCellReuseIdentifier: kUserProfileCellReuseId)
}
//MARK: TableView Methods -
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 5
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let sessionCell: UserProfileTableCell.self = tableView.dequeueReusableCell(withIdentifier: kUserProfileCellReuseId, for: indexPath) as! UserProfileTableCell.self
cell.titleLabel.text = “TEST”
return sessionCell
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView.deselectRow(at: indexPath, animated: true)
}
}
class UserProfileTableCell: UITableViewCell {
//Set the "kUserProfileCellReuseId" in nib to register identifier.
let kUserProfileCellReuseId = "kUserProfileCellReuseId"
//MARK: - Override Methods
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
setUIComponents()
}
private func setUIComponents(){
}
}
You never declare that your view controller conforms to the UITableViewDataSource or UITableViewDelegate protocols. Given that you don't do that, you would not be able to set your view controller as the data source or delegate of your table view.

Data loading issue in Table View in IOS

I have a table view controller in my view controller. When I give it static number of rows and cell for row index method name it shows nothing to me in the table view. I have also reload the table view but it isn't showing I don't know why is it so,
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return messages.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = UITableViewCell (style: .subtitle, reuseIdentifier: "cellID")
let message = messages[indexPath.row]
cell.textLabel?.text = message.text
return cell
}
Recheck if u have set
tableView.delegate = self
tableView.datasource = self
Also put a breakpoint on cellForRowAtIndexpath to check if code runs through the block.
Also Recheck the cellIdentifier (cellID) is correct or not.
class ViewController:UIViewController,UITableViewDataSource,UITableViewDelegate {
//Getting the reference variables of storyboard
#IBOutlet weak var tableView:UITableView!
var messages = [String]()
override func viewDidLoad() {
super.viewDidLoad()
//Add some packages
messages.append("Super")
messages.append("Free ")
messages.append("Miscellaneous")
messages.append("All ")
tableView.datasource = self
tableView.delegate = self
}
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return messages.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = UITableViewCell (style: .subtitle, reuseIdentifier: "cellID")
let message = messages[indexPath.row]
cell.textLabel?.text = message.text
return cell
}
}
Use this . This one works for me
class yourViewController: UIViewController,UITableViewDataSource,UITableViewDelegate {
#IBOutlet weak var tableView:UITableView!
override func viewDidLoad() {
super.viewDidLoad()
tableView.datasource = self
tableView.delegate = self
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return messages.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell=tableView.dequeueReusableCell(withIdentifier: "cellID",for : indexPath)
let message = messages[indexPath.row]
cell.textLabel?.text = message.text
return (cell)
}
}

Swift 3.0 Textfield in a TableViewCell not showing up

I am trying to display a textfield on a tableview using a custom cell. I think I have set up the delegation protocol properly, but when loaded, the tableview doesn't show the textfield. I have added a textfield into the customcell, set the class to CustomCell, and changed the identifier to "Cell", but I am not sure what else I am missing.
view controller with tableview:
#IBOutlet weak var tableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
tableView.delegate = self
tableView.dataSource = self
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
print("Hello")
}
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return data.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! CustomCell
cell.cellDelegate = self
cell.contentView.bringSubview(toFront: cell.textField)
cell.textField.delegate = self as? UITextFieldDelegate
cell.textField.text = "Test"
return cell
}
func didPressTextField(indexPath: IndexPath) {
print("textfield was tapped")
}
custom cell VC:
protocol CustomCellDelegate : class {
func didPressTextField(indexPath: IndexPath)
}
class CustomCell: UITableViewCell {
weak var cellDelegate: CustomCellDelegate?
var indexPath: IndexPath!
override func awakeFromNib() {
super.awakeFromNib()
self.cellDelegate = nil
// Initialization code
}
#IBOutlet weak var textField: UITextField!
#IBAction func textFieldWasTapped(_ sender: UITextField) {
self.cellDelegate?.didPressTextField(indexPath: indexPath)
}
Your data source is empty.
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// data is not containing any value
return data.count
}
Check data.count it should have some data and also if that is custom cell with XIB then you need to register cell in view didload
self.tableView.register(UINib(nibName: "Your Cell XIB name", bundle: nil),
forCellWithReuseIdentifier: "Cell")
Check your data.count. it must return value greater than 0 otherwise your tableView is showing with 0 rows and nothing is display in tableView.
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// debug at this point check what is value of data.count its must be greater than 0
return data.count
}

how handle click cell in UITableViewController

I would like to handle click each cell in my controller but my log doesn't show anything !
class RightMenuController: UITableViewController {
let row_items = ["دسته بندی", "ثبت نام/ورود"]
override func viewDidLoad() {
navigationController?.navigationBar.isHidden = true
super.viewDidLoad()
self.tableView.delegate = self
self.tableView.dataSource = self
// Uncomment the following line to preserve selection between presentations
// self.clearsSelectionOnViewWillAppear = false
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK: - Table view data source
override func numberOfSections(in tableView: UITableView) -> Int {
// #warning Incomplete implementation, return the number of sections
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// #warning Incomplete implementation, return the number of rows
return row_items.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "LabelCell", for: indexPath)
cell.textLabel?.text = row_items[indexPath.row]
return cell
}
/*
// Override to support conditional editing of the table view.
override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
// Return false if you do not want the specified item to be editable.
return true
}
*/
/*
// Override to support editing the table view.
override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
if editingStyle == .delete {
// Delete the row from the data source
tableView.deleteRows(at: [indexPath], with: .fade)
} else if editingStyle == .insert {
// Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view
}
}
*/
/*
// Override to support rearranging the table view.
override func tableView(_ tableView: UITableView, moveRowAt fromIndexPath: IndexPath, to: IndexPath) {
}
*/
/*
// Override to support conditional rearranging of the table view.
override func tableView(_ tableView: UITableView, canMoveRowAt indexPath: IndexPath) -> Bool {
// Return false if you do not want the item to be re-orderable.
return true
}
*/
/*
// 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.destinationViewController.
// Pass the selected object to the new view controller.
}
*/
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
print(self.row_items[indexPath.row]) // not print anything
}
}
Try this instead of your didSelectRow-method:
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
print(self.row_items[indexPath.row])
}
The "method signature" (function name) that you are using for the didSelect method is incorrect. What you have listed in your current implementation is the "Swift 2 Version". You might note the way that the argument labels are separated to make the functions a bit more readable like in tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath)
This same renaming style should be applied to didSelectRowAtIndexPath. Here is the full code you can use to test this out in a playground.
import UIKit
class RightMenuController: UITableViewController {
let row_items = ["دسته بندی", "ثبت نام/ورود"]
override func viewDidLoad() {
// We must register a cell manually since there is no storyboard
tableView.register(UITableViewCell.self, forCellReuseIdentifier: "LabelCell")
navigationController?.navigationBar.isHidden = true
super.viewDidLoad()
self.tableView.delegate = self
self.tableView.dataSource = self
}
// MARK: - Table view data source
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return row_items.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "LabelCell", for: indexPath)
cell.textLabel?.text = row_items[indexPath.row]
return cell
}
// Old Swift 2 method signature
//func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
print(self.row_items[indexPath.row]) // not print anything
}
}
// Create the ViewController
let right = RightMenuController(style: .plain)
// Ask the Playground to show your ViewController in the Assistant (2 rings - Right side view)
import PlaygroundSupport
PlaygroundPage.current.liveView = right

Get indexPath for cell of UITable embedded in UITableViewCell

So here is the structure of the TableView:
There is a main UITableView, and inside each UITableViewCell there is another UITableview
Screenshot:
Each of the UITableViewCells have been designed as Custom Views and have been added by loading it from the Nib in the cellForRowAtIndexPath function.
What I want to do is for any option selected in the inner Table Views I want to get the index path of the cell that the Table View is embeded in.
Document Layout:
I tried to follow the delegate approach mentioned by Paulw11 here:
swift: how to get the indexpath.row when a button in a cell is tapped?: StackOverflow
Note: The method suggested by Paulw11 works perfectly
Code(TableVC):
class TableVC: UITableViewController, QuestionCellDelegate {
override func viewDidLoad() {
super.viewDidLoad()
// Uncomment the following line to preserve selection between presentations
// self.clearsSelectionOnViewWillAppear = false
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK: - Table view data source
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// #warning Incomplete implementation, return the number of rows
return 5
}
override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 220.0
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = Bundle.main.loadNibNamed("QuestionCell", owner: self, options: nil)?.first as! QuestionCell
cell.delegate = self
return cell
}
func sendCellInfo(cell: UITableViewCell) {
print(cell)
let indexPathForQuestion = tableView.indexPath(for: cell)
print(indexPathForQuestion)
}}
Code(QuestionCell):
protocol QuestionCellDelegate: class {
func sendCellInfo(cell: UITableViewCell)
}
class QuestionCell: UITableViewCell, UITableViewDelegate, UITableViewDataSource{
#IBOutlet weak var optionsTableview: UITableView!
var delegate: QuestionCellDelegate?
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
self.optionsTableview.delegate = self
self.optionsTableview.dataSource = self
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = Bundle.main.loadNibNamed("OptionsCell", owner: self, options: nil)?.first as! OptionsCell
return cell
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 4
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let selectedCell = optionsTableview.cellForRow(at: indexPath)
print("selectedCell")
self.delegate?.sendCellInfo(cell: selectedCell!)
}}
Code(OptionsCell):
class OptionsCell: UITableViewCell {
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
}}
Note: The current O/P is nil
Note: Code changed as per commented by pbasdf, realised the mistake
Found the solution due to pbasdf comment:
Delegate Function in TableVC:
func sendCellInfo(cell: UITableViewCell) {
/*** Take the cell passed and convert to a CGPoint wrt to TableView ***/
let cellPosition: CGPoint = cell.convert(cell.bounds.origin, to: self.tableView)
/*** wrt to CGPoint find index on current TableView ***/
/*** Returns as Section,Cell ***/
let indexPathForSelectedCell = (tableView.indexPathForRow(at: cellPosition)?.row)
print(indexPathForSelectedCell)
}
The following answer is added #Supratik Majumdar request for the logic which I said.
Supratik try using the following code, I hope you will get your need done.
//Initialize your question or answer in viewDidLoad or where ever you like to as shown below
self.questionArray = ["Question1", "Question2"]
self.optionArray = [["Option 1", "Option 2", "Option 3", "Option 4"], ["Option 1", "Option 2", "Option 3", "Option 4"]]
//Make us of the following tableview delegate & datasource code
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return self.questionArray.count
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return self.OptionArray[section].count
}
func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String {
return self.questionArray[section]
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! UITableViewCell
let currentOptionArray = self.questionArray[section]
let currentOption = currentOptionArray[indexPath.row]
cell.textLabel.text = currentOption
return cell
}
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
let selectedIndex = indexPath
let selectedQuestionIndex = indexPath.section
let selectedOptionIndex = indexPath.row
//Make use of the data you need in the above values
}
Use this:
tableView.cellForRowAtIndexPath(YourIndexPath) as! OptionCell
You can do your own indexPath as global variable and filing it on didSelectRow method
YourIndexPath = indexPath

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