when I press the button active in tableview

Question

When I press the button, I want to run the Tableview cellForRowAt function. But I don't want to call cellForRowAt when I don't press the button. Because the cellForRowAt function works as soon as the application opens. Press the button and if newdevicechipnumber.ishidden == false I want to run the function in . I want that function to work when I press the Newdeviceadd button.

    class MainTableViewController: UITableViewController {

 let newdeviceadd: UILabel = {

        let topAlignment: SMIconLabel.VerticalPosition = .top

        let labelLeft = SMIconLabel()
        labelLeft.isHidden = true
        labelLeft.text = "Cihazı Ekle"
        labelLeft.font = UIFont(name: "Avenir-Black", size: 23)
        labelLeft.textColor = UIColor.flatWhite
        labelLeft.translatesAutoresizingMaskIntoConstraints = false
        labelLeft.icon = UIImage(named: "homepage")    // Set icon image
        labelLeft.iconPadding = 5                  // Set padding between icon and label
        labelLeft.numberOfLines = 0                // Required
        labelLeft.iconPosition = ( .left, topAlignment )
        labelLeft.textAlignment = .left
        return labelLeft
    }()

    var items: [Device] = []
        var itemsnew: [NewDevice] = []

        let cellId: String = "cellId"

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


            let cell = tableView.dequeueReusableCell(withIdentifier: cellId, for: indexPath) as! DeviceTableViewCell
            let selectedIndexPaths = tableView.indexPathsForSelectedRows
            let rowIsSelected = selectedIndexPaths != nil && selectedIndexPaths!.contains(indexPath)
            cell.accessoryType = rowIsSelected ? .checkmark : .none

            if newdevicechipnumber.isHidden == false {
                let deviceItemNew: NewDevice = itemsnew[indexPath.row]
                cell.new = deviceItemNew
                cell.titleNew.text = deviceItemNew.title
                cell.title1New.text = deviceItemNew.places
                cell.titlesaatNew.text = deviceItemNew.time
                cell.buttonNew.isOn = deviceItemNew.state
                cell.buttonNew.isHidden = hideBtn
                cell.buttonNew.addTarget(self, action: #selector(refreshDataNew), for: .touchUpInside)

             }

    }

Answer 1

One way to do this would be to store some state in your ViewController and then flip that state once you push the button. If you do that, then you could tell your numberOfRowsInSection function to return zero if the button has not been pressed yet and return the true number if the button as been pressed.

Answer 2

Option 1: You can use a bool to trigger the population of your UITableView . Let's say we call it shouldPopulate , and we define it at the top of your controller.

var shouldPopulate: Bool = false

Use shouldPopulate to trigger the correct number of rows or 0 .

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return shouldPopulate ? yourNumberOfRows : 0
}

Then when your button is tapped, you define shouldPopulate to true and reload the data.

@IBAction func buttonTapped(_ sender: Any) {
    self.shouldPopulate = true
    self.tableView.reloadData()
}

Option 2: You can use a UIViewController with a UITableView inside if you want to get specific a behavior, it would be better than UITableViewController .

Instead of setting the TableView Data Source in viewDidLoad for instance, define it inside your action function.

@IBAction func buttonTapped(_ sender: Any) {
    self.tableView.dataSource = self
}

Setting data source should reload the data, you don't need to call reloadData()