将文本从单元格移动到另一个视图控制器中的文本标签

Question

I have created an app that displays 10 random numbers in a table view. This is the code I used

override func numberOfSections(in tableView: UITableView) -> Int {
    return 1
}

override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return 10
}


override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "ShowNumber", for: indexPath)

    // Configure the cell...
    cell.textLabel?.text = "\(indexPath.row + 1): \(Int(arc4random_uniform(10001)))"

    return cell
}

Now I want to be able to click on one cell and be taken to another view controller and in the center of the page it displays the random number. I have the view controller all set up and linked to the original table view. I'm just having trouble passing my data through the segue. This is what I have so far. I know it unfinished, I just don't know what to do.

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {   
    if segue.identifier == "showRandomNumber" {
        let controller = segue.destination as! ShowNumberTableViewController
        let selectedRow = (tableView.indexPathForSelectedRow as NSIndexPath?)?.row ?? 0
        controller.LabelText = 
    }

The LabelText is the name of the label that I want to pass the data to, but I don't know how to

Answer 1

Using the indexPathForSelectedRow , you can get a reference to the cell that triggered the segue. You can then access the textLabel within that cell, get its value, and pass it to the next view controller.

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {   
    if segue.identifier == "showRandomNumber" {
        let controller = segue.destination as! ShowNumberTableViewController
        if let indexPath = tableView.indexPathForSelectedRow {
            let cell = tableView.cellForRowAtIndexPath(indexPath) as UITableViewCell
            if let textToPass = cell.textLabel.text {
                controller.labelText = textToPass
            }
        }
    }
}

Then in ShowNumberTableViewController you want a var labelText and in your viewDidLoad() you can assign it to the textLabel in that view controller with

centerLabel.text = labelText

Answer 2

The way you are doing, the numbers will change when you scroll the table view. I think you should save the numbers in an array.

About how to grab the selected number in the prepareForSegue: I would do this way:

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if segue.identifier == "showRandomNumber" {
        if let cell = sender as? UITableViewCell, indexPath = tableView.indexPathForCell(cell) {
            let selectedNumber = numbers[indexPath.row]
            controller.labelText = String(selectedNumber)
        }
    }
}