tableView.reloadData() Table not updating

Question

The table does not display the updated array to return to the cell. When I launch the app I get blank cells. All permissions have been given in the storyboard. I tried the tableView.reloadData() everywhere but can't seem to make it work either. If anyone can explain where Im going wrong that would really help me get better.

class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {

@IBOutlet weak var slider: UISlider!

@IBAction func sliderSelector(_ sender: Any) {
    tableGenerate()
}

var arrayTable = [Int]()

public func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return arrayTable.count
}

public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

    let cell = UITableViewCell(style:UITableViewCellStyle.default, reuseIdentifier: "Cell")
    cell.textLabel?.text = String(arrayTable[indexPath.row])
    tableView.reloadData()
    return cell
}

func tableGenerate () {
    var tableMultiplier = 1
    while tableMultiplier <= 50 {
        arrayTable.append(tableMultiplier * Int(slider.value))
        tableMultiplier += 1
        print(arrayTable)
    }
}

Why would you call tableView.reloadData() inside cellForRowAt? That puts you in in infinite loop, since it will again call cellForRowAt... You only need to call tableView.reloadData() if you change the data source after your table view was set up. — David Pasztor
– David Pasztor, Commented Aug 17, 2017 at 13:34
Yes, so you should call tableView.reloadData() from inside sliderSelector or rather do it from inside tableGenerate()... @Dev0urCode check my answer. — David Pasztor
– David Pasztor, Commented Aug 17, 2017 at 13:37
You only have to populate arrayTable and call tableView.reloadData() once. That will get the number of rows from numberOfRowsInSection and will ask you for the initialized cell (in cellForRowAt). So cellForRowAt should return the UITableViewCell only, and do nothing more. — Alejandro Iván
– Alejandro Iván, Commented Aug 17, 2017 at 13:44
@DávidPásztor if I put tableview.reloaddata in the slider section I get Ambiguous reference to member 'tableView(_:numberOfRowsInSection:)' — Dev0urCode
– Dev0urCode, Commented Aug 17, 2017 at 13:50

Abhishek Jain · Accepted Answer · 2017-08-17 13:47:46Z

3

Add outlet of tableview like this and connect with table in storyboard-

@IBOutlet weak var tableView1: UITableView!

Change code to this -

class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {

@IBOutlet weak var slider: UISlider!
@IBOutlet weak var tableView1: UITableView!

@IBAction func sliderSelector(_ sender: Any) {
    tableGenerate()
}

var arrayTable = [Int]()

public func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return arrayTable.count
}

public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

    let cell = UITableViewCell(style:UITableViewCellStyle.default, reuseIdentifier: "Cell")
    cell.textLabel?.text = String(arrayTable[indexPath.row])
    return cell
}

func tableGenerate () {
    var tableMultiplier = 1
    while tableMultiplier <= 50 {
        arrayTable.append(tableMultiplier * Int(slider.value))
        tableMultiplier += 1
    }
        print(arrayTable)
    tableView1.reloadData()

}

edited Aug 17, 2017 at 13:47

answered Aug 17, 2017 at 13:37

Abhishek Jain

4,7373 gold badges34 silver badges31 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

Dev0urCode Over a year ago

if I do that i get Ambiguous reference to member 'tableView(_:numberOfRowsInSection:)' at tableView.reloadData line

Dev0urCode Over a year ago

than that gives me Use of unresolved identifier 'tableView1'

Dev0urCode Over a year ago

You are right; progress !! I forgot to create the outlet ! I created @IBOutlet weak var table: UITableView! and it works by updating on the first move of the slider to the initial slider value but when I move the slider further it does not update anymore.

Dev0urCode Over a year ago

using table.reloadData()

Dev0urCode Over a year ago

I found the issue, forgot to add arrayTable = [] in my sliderslector so I thought the table was not updating when in fact it was just getting bigger. Thanks a million for your help !

David Pasztor · Accepted Answer · 2017-08-17 13:54:14Z

By calling tableView.reloadData() inside cellForRowAt, you create an infinite loop, since reloadData() automatically calls cellForRowAt. You need to move reloadData() inside tableGenerate(), since it should only be called when your data source is changed.

You also need to create an IBOutlet for your tableView in Storyboard. Since you are not using a UITableViewController, you need to do this manually.

class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {

    @IBOutlet weak var tableView: UITableView!
    @IBOutlet weak var slider: UISlider!

    @IBAction func sliderSelector(_ sender: Any) {
        tableGenerate()
    }

    var arrayTable = [Int]()

    public func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return arrayTable.count
    }

    public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = UITableViewCell(style:UITableViewCellStyle.default, reuseIdentifier: "Cell")
        cell.textLabel?.text = String(arrayTable[indexPath.row])
        return cell
    }

    func tableGenerate () {
        var tableMultiplier = 1
        while tableMultiplier <= 50 {
            arrayTable.append(tableMultiplier * Int(slider.value))
            tableMultiplier += 1
            print(arrayTable)
        }
        tableView.reloadData()
    }
}

Dev0urCode · Accepted Answer · 2017-08-17 14:21:11Z

-1

forgot to create the table outlet ! I also forgot to reset the array with the array slider with arrayTable = [] now it works fine

answered Aug 17, 2017 at 14:21

Dev0urCode

831 silver badge11 bronze badges

Collectives™ on Stack Overflow

tableView.reloadData() Table not updating

3 Answers 3

5 Comments

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

5 Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related