如何将选定单元格中的数据传递给另一个视图控制器？

Question

The piece of code below prints the content of whichever cell is clicked on in my TableView.

override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath)  {
    print(self.cell[indexPath.row])
}

I want to use the result that is printed in a label on another ViewController.

How do I get the string value from the function and then use it on on the other view? My thought is to use a global variable but I need to get the string value out first.

Answer 1

At first, when you create a tableView , you have to collect data ( string here) of cells in an array or another data collection. And you can get a needed data ( strings ) with indexPath variable in the method didSelectRowAt . And you can pass the string to another ViewController (let use SecondViewController ) with several ways.

Here is an example:

// declaration an array of your strings
var array : [String] = ["First", "Second", "Third", ...]
...
// getting a string from method:
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath)  {
let string = array[indexPath.row]
print(string)
// next, for example, you need to pass the string to a singleton SecondViewController with static var **main**:
SecondViewController.main?.neededString = string
}

Don't forget update in async DispatchQueue:

DispatchQueue.main.async {
    SecondViewController.main?.updateUI(withString : string)
}

Answer 2

For example, You can use simple organization of a singleton of another ViewController ( SecondScreen ) with var main (in case, as usual, when SecondScreen inited via a Storyboard):

class SecondScreen : UIViewController {
    // 1. add this var
    static var main : SecondScreen? = nil

    // 2. Your some UI element
    @IBOutlet weak var textButton: UIButton!

    // 3. add this method
    func updateUI(string : String) {
        textButton.setTitle(string, for: .normal)
    }

    // 4. setting a var
    override func viewDidLoad() {
        if SecondScreen.main == nil {
            SecondScreen.main = self
        }
    }

    // ... another your and standard methods
}

And you can update your SecondScreen like this:

    let v = SecondScreen.main
    v?.updateUI(string: "yourString")

Also I recommend you to call method async:

DispatchQueue.main.async {
    SecondScreen.main?.updateUI(withString : string)
}

I suggest you to learn more about singletons...