I've created a ViewController with my Storyboard linked to it. I've done this before and it has worked fine. This time tho, when I use almost the exact same code for the table view and the table view cell, it returns a nil error when running. I am not sure what the reason exactly is.
//
// IngView1.swift
// Fake
//
// Created by Ian Dong on 11/16/20.
//
import UIKit
class IngView1: UIViewController, UITableViewDataSource {
#IBOutlet weak var display: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
display.dataSource = self
}
var data = ["Oil 5","Beef 3","Chicken 5","Potato 4","Cheese 3","Fish 3","Cabage 4"]
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return data.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "IngReUse")! // Thread 1: Fatal error: Unexpectedly found nil while unwrapping an Optional value
let text = data[indexPath.row]
cell.textLabel?.text = text
return cell
}
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
}
Are you sure you properly set prototype cell's identifier? You can do this in the storyboard.
Or if you're not using prototype cell, you can register it in code
display.register(UITableViewCell.self, forCellReuseIdentifier: "IngReUse")
Related
I'm stuck with the following, any inputs would be highly appreciated.
My app has a UITableViewController with custom cells. Let's name its UITableView as TABLE VIEW-1. I am using XIB as its custom cell. Inside that xib, there is another UITableView, (TABLE VIEW-2), with another XIB as its custom cell.
My question is, How can I reload cells of (TABLE VIEW-2) from (TABLE VIEW-1) once I get data from an API in (TABLE VIEW-1). I want to use delegate and protocols to do this.
OR, What would be the correct way of performing this and how would I go about it?
Create a reference of TableView1 in the TableView2 ViewController. You can do this by
-- Open the Assistant Editor
-- Right-click and drag from your UI element (i.e. label) to the code file
-- Xcode auto inserts code for you to create the name and connection
Then call tableView2.reloadData(), where tableView2 is the name of the outlet you just created.
Create a reference of the TABLE VIEW-2 in the TABLE VIEW-1 custom cell (TABLE VIEW-1 CELL)
Create a method inside TABLE VIEW-1 CELL to reload its data alone with the TABLE VIEW-2 (Optional but useful to organize your code)
Inside the tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell of the TABLE VIEW-1 call reload function
class ViewController: UIViewController {
#IBOutlet weak var mainTable: UITableView!
let sampleData = [
(section: "News", SubSections: [
"Breaking news",
"Current Affairs",
"Local"
]) ]
override func viewDidLoad() {
super.viewDidLoad()
self.mainTable.estimatedRowHeight = 200
self.mainTable.rowHeight = UITableView.automaticDimension
let nib: UINib = UINib(nibName: String(describing: MainCell.self), bundle: Bundle.main)
self.mainTable.register(nib, forCellReuseIdentifier: String(describing: MainCell.self))
}
}
extension ViewController: UITableViewDataSource {
func numberOfSections(in tableView: UITableView) -> Int {
1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
self.sampleData.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell: MainCell = tableView.dequeueReusableCell(withIdentifier: String(describing: MainCell.self), for: indexPath) as! MainCell
let sectionData = self.sampleData[indexPath.row]
cell.setUpData(title: sectionData.section, data: sectionData.SubSections)
return cell
}
}
class MainCell: UITableViewCell {
#IBOutlet weak var sectionTitle: UILabel!
#IBOutlet weak var internalTable: UITableView!
var tableData:[String]?
override func awakeFromNib() {
super.awakeFromNib()
self.internalTable.estimatedRowHeight = 200
self.internalTable.rowHeight = UITableView.automaticDimension
let nib: UINib = UINib(nibName: String(describing: InsideCell.self), bundle: Bundle.main)
self.internalTable.register(nib, forCellReuseIdentifier: String(describing: InsideCell.self))
}
func setUpData(title: String, data:[String]) {
self.sectionTitle.text = title
self.tableData = data
self.internalTable.reloadData()
}
}
extension MainCell: UITableViewDataSource {
func numberOfSections(in tableView: UITableView) -> Int {
1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
self.tableData?.count ?? 0
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell: InsideCell = tableView.dequeueReusableCell(withIdentifier: String(describing: InsideCell.self), for: indexPath) as! InsideCell
if let subSectionData = self.tableData?[indexPath.row] {
cell.subSectionTitle.text = subSectionData
}
return cell
}
}
class InsideCell: UITableViewCell {
#IBOutlet weak var subSectionTitle: 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
}
}
I am using a Custom TableViewCell in TableViewController.
Even the data is getting populated but my TableViewCell does not display it.
Here is my Custom TableViewCell Code
class PlaceItemCellCustom: UITableViewCell {
#IBOutlet weak var placeFace: UILabel?
#IBOutlet weak var placeName: UILabel?
override func awakeFromNib() {
super.awakeFromNib()
}
}
Here is my TableViewContoller
class PlaceListViewController: UITableViewController {
override func viewDidLoad() {
super.viewDidLoad()
loadListFromSource()
}
// Other code
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return places.count
}
override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 100
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let place = places[indexPath.row]
// I am getting the data
print(place.placeName?.description ?? " " )
let customCell = tableView.dequeueReusableCell(withIdentifier: "PlaceListIdentifier", for: indexPath) as! PlaceItemCellCustom
customCell.placeName?.text = place.placeName
return customCell
}
}
What am I missing here? I am new to IOS app development.
Found similar questions but did not help
Edit: It was working fine for the default TableViewCell.
But when I changed it to custom TableViewCell it does not work. I have set the class name in the storyboard as well.
Here is my Storyboard
Here is the output
As much as I can understand you must have forgotten to connect the IBOutlet of placeName in PlaceItemCellCustom:
In your PlaceItemCellCustom keep placeName as :
#IBOutlet weak var placeName: UILabel!
and in cellForRowAt:
customCell.placeName.text = place.placeName
in this way if you forgot to connect segue Xcode will throw error as :
Thread 1: Fatal error: Unexpectedly found nil while implicitly unwrapping an Optional value
You can read more about it here :
https://cocoacasts.com/should-outlets-be-optionals-or-implicitly-unwrapped-optionals
You need using this method for get data.
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return places.count
}
I'm setting up a tableview with customtableview cell, but when i run the app, the data is not shown.
I already check all the connection, identifier, class name, etc
import UIKit
class ViewController: UITableViewController {
#IBOutlet var testingTableView: UITableView!
var data = ["Indomie","Kacang Tanah","Soya"]
override func viewDidLoad() {
super.viewDidLoad()
testingTableView.register(UINib(nibName: "TableViewCell", bundle: nil), forCellReuseIdentifier: "customCell")
// Do any additional setup after loading the view.
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = testingTableView.dequeueReusableCell(withIdentifier: "customCell", for: indexPath) as! customTableViewCell
cell.customLabel.text = data[indexPath.row]
return cell
}
override func numberOfSections(in tableView: UITableView) -> Int {
return data.count
}
}
This is my code for the table view, it's should call the cellforrowat but it's not
You are missing tableView(_:numberOfRowsInSection:) implementation.
You have number of data.count section, but each section has 0 row.
Try replacing numberOfSections(in:) to tableView(_:numberOfRowsInSection:)
I guess you need additional code as below-
testingTableView.delegate = self
testingTableView.datasource = self
testingTableView.reloadData() // I think you missed it!
1). Add this line
#IBOutlet var testingTableView: UITableView! {
didSet {
testingTableView.delegate = self
testingTableView.dataSource = self
}
}
2). You also can add this feature via Stroyboard. Click on your table and using right click drag the pointer on ViewController and add delegate and dataSource.
And i think you missed
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 0 //As per your need.
}
You are using the wrong API, numberOfSections returns the number of sections but you have to return the number of rows
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int { {
return data.count
}
There is no need to override numberOfRowsInSection, the default value is 1.
And delete
#IBOutlet var testingTableView: UITableView!
There is an implicit tableView property of UITableViewController
I cannot get this to segue to another TableViewController. I keep getting a crash... I know it is because it is going through the NavigationController and I do not know how to segue from the main controller to pass it and go to the tableView. Heres the look
the segue from the navControl to the tableView is called "ChildsInfo"
Here is what I am trying and crashing.
class PagesViewController: UIViewController, UITableViewDelegate {
#IBOutlet weak var pagesTableView: UITableView!
#IBOutlet weak var infoProgressBar: UIProgressView!
let pages = ["Page 1","Page 2","Page 3"]
var myIndex = 0
var selectedPage: String?
override func viewDidLoad() {
super.viewDidLoad()
pagesTableView.dataSource = self
pagesTableView.delegate = self
// Do any additional setup after loading the view.
}
}
extension PagesViewController: UITableViewDataSource {
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "pagesTableViewCell")
cell?.textLabel?.text = pages[indexPath.row]
return cell!
}
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return pages.count
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 71.0
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
if indexPath.row == 0 {
performSegue(withIdentifier: "ChildsInfo", sender: self)
}
}
}
Based on the images you have posted I'm assuming the crash you are getting is that the segue is not found. This is because you should be trying to perform the segue to the navigation controller itself from the table view (i.e. the link on the left in your image). The navigation controller then has a root view controller and you can push others onto the stack as required.
I am trying to build a times tables app with a slider and a UITableView, but it gives me the SIGABRT error. I have tried relinking every outlet and action as well as redoing it from scratch, but it still won't seem to work.
Since I cannot paste it in here correctly formatted, I put it on pastebin.com
Debug code: http://pastebin.com/cBaALXWq
ViewController.swift
import UIKit
class ViewController: UIViewController, UITableViewDelegate {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBOutlet weak var sliderValue: UISlider!
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 50
}
#IBAction func sliderMoved(sender: AnyObject) {
var timesTableIndex: Int = Int(sender.value)!
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = UITableViewCell(style: UITableViewCellStyle.Default, reuseIdentifier: "Cell")
cell.textLabel?.text = String(timesTableIndex*indexPath.row+1)
return cell
}
}
}
AppDelegate.swift; gives error in line 4
import UIKit
#UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
EDIT
#IBOutlet weak var sliderValue: UISlider!
var timesTableIndex: Int?
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 50
}
#IBAction func sliderMoved(sender: AnyObject) {
timesTableIndex = Int(sliderValue.value * 50)
}
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = UITableViewCell(style: UITableViewCellStyle.Default, reuseIdentifier: "Cell")
cell.textLabel.text = String(timesTableIndex*(1+indexPath.row))
return cell
}
I looks like you've added cellForRowAtIndex: inside #IBAction method. What you need to do is to take it out from the method. In addition you need set the timesTableIndex variable as global so that it can be accessed in cellForRowAtIndexPath: and call the reloadData method on tableView when you call sliderMoved: method.
var timesTableIndex: Int = 0 // Now global variable
#IBAction func sliderMoved(sender: AnyObject) {
timesTableIndex = Int(sender.value)!
self.tableView.reloadData()
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath)
cell.textLabel?.text = "\(timeTableIndex * indexPath.row + 1)"
return cell
}
Also it seems that you are not using dequeueReusableCellWithIdentifier method on your table view, so I've updated the code to use it. Not that you need to set the Cell reuse identifier in your storyboard.
This should be your tableview code if you have created tableview in the storyboard
#IBOutlet weak var sliderValue: UISlider!
#IBOutlet weak var tableview: UITableView!
var timesTableIndex: Int = 0
#IBAction func sliderMoved(sender: AnyObject) {
timesTableIndex = Int(sliderValue.value * 50)
tableview.reloadData()
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return timesTableIndex
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath)
cell.textLabel!.text = String(1*(1+indexPath.row))
return cell
}
If you have created your cell in the storyboard set the CellReuseIdentifier as 'cell' in the storyboard else you can register the class in the like
override func viewDidLoad() {
super.viewDidLoad()
//tableView is IBOutlet instance of UITableview
tableView.registerClass(UITableViewCell.self, forCellReuseIdentifier: "test")
}
Also please check you have set the tableview delegate/datasource in the storyboard tableview object
I've managed to solve the problem. I accidentally put the function which sets up the prototype cell outside the ViewController class, that explains everything. Thank you for helping me!