UITableView reloadData() Swift2 not reloading data

Question

I am newbie in Swift and trying to show multiplication table in UITableView and changing the data based on the slider value. The model is updated on changing the slider position but the tableView is not showing the update for currently visible portions of the table. The update happens when new rows are added or removed during scrolling. Some code:

class ViewController: UIViewController, UITableViewDelegate {

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

let maxCount = 50
var multiplierArray: [String] = []

override func viewDidLoad() {
    super.viewDidLoad()
    let number: Int = Int(slider.value)
    populateData(number)
}

func populateData(number: Int) {
    var i = 0
    multiplierArray.removeAll()
    while i < maxCount {
        let table = i + 1
        let str = "\(number) x \(table) = \(table * number)"
        print(str)
        multiplierArray.append(str)
        i += 1
    }
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
}

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

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell{
    let cell = UITableViewCell(style: UITableViewCellStyle.Default, reuseIdentifier: "Cell")
    cell.textLabel?.text = multiplierArray[indexPath.row]
    print("cellForRowAtIndexPath called")
    return cell
}

func numberOfSectionsInTableView(tableView: UITableView) -> Int{
    return 1
}

@IBAction func sliderValueChanged(sender: UISlider) {
    let number: Int = Int(slider.value)
    populateData(number)
    tableView.reloadData()
    print("slider value changed" + String(number))
}
}

I read quite a few posts on this issue but couldn't figure out the issue in above code. My understanding is that tableView.reloadData() should update the view when the underlying model is changed like notifyDataSetChanged() in android. Am I missing some functions of tableView?

Can you show us if you assigned your table view's delegate and data source to your current view controller? — Happiehappie
– Happiehappie, Commented Jul 20, 2016 at 9:52

crisisGriega · Accepted Answer · 2016-07-20 09:53:32Z

1

Your ViewController class needs to implement the UITableViewDataSource protocol, no need to implement the UITableViewDelegate here. And you need to assign it in the viewDidLoad function (for example):

override func viewDidLoad() {
    super.viewDidLoad()
    let number: Int = Int(slider.value)
    populateData(number)
    tableView.datasource = self;
}

Quick note: UITableViewDatasource is the one in charge for populating the UITableView with data. UITableViewDelegate cares about cells height and selecting states.

answered Jul 20, 2016 at 9:53

crisisGriega

8627 silver badges17 bronze badges

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

Collectives™ on Stack Overflow

UITableView reloadData() Swift2 not reloading data

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related