ViewController加载两次Xcode iOS

Question

I know what causes it to load twice, but I do not know how to fix the problem. I have looked through many other questions at the same topic, but any of those are matching to my problem.

So here's the code

override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath){

        let selectedCell = tableView.cellForRowAtIndexPath(indexPath)! as UITableViewCell
        super.performSegueWithIdentifier("TVtoVCSegue", sender: selectedCell)
        print("kolm")
    }

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {

        if segue.identifier == "TVtoVCSegue" {
            let otherViewController = segue.destinationViewController as! TTDetailCntr

            if let cell = sender as? UITableViewCell, text = cell.textLabel?.text {
                otherViewController.CurrentClass = text
            }
        }
    }

As I understand, in tableview function

super.performSegueWithIdentifier("TVtoVCSegue", sender: selectedCell)

Calls out the view to load and the function below itself calls out the view to load,

func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?)

both will load the view so I tried to integrate those methods and I tried to do sth like this:

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    let indexPath = tableView.indexPathForSelectedRow! as NSIndexPath
    let selectedCell = tableView.cellForRowAtIndexPath(indexPath)! as UITableViewCell

    super.performSegueWithIdentifier("TVtoVCSegue", sender: selectedCell)

    if segue.identifier == "TVtoVCSegue" {
        let otherViewController = segue.destinationViewController as! TTDetailCntr

        if let cell = sender as? UITableViewCell, text = cell.textLabel?.text {
            otherViewController.CurrentClass = text
        }
    }
}

But It says an error if I try to access the view that loaded twice before: The error comes from the line:

super.performSegueWithIdentifier("TVtoVCSegue", sender: selectedCell)

And the error is:

warning: could not load any Objective-C class information. This will significantly reduce the quality of type information available.
(lldb) 

The idea of the code is to get the indexPath value and then pass it to another ViewController

Answer 1

The segue that you've created is most probably from a tableViewCell rather than the UIViewController

Delete the segue and create one from the UIViewController instead.

Ctrl + drag from the circle highlighted in the image to your destination VC.

This will solve this problem.

Answer 2

write

self.performSegueWithIdentifier

and check instead of

super.performSegueWithIdentifier

Its working fine with this

func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath){     
    let selectedCell = tableView.cellForRowAtIndexPath(indexPath)! as UITableViewCell
    self.performSegueWithIdentifier("TVtoVCSegue", sender: selectedCell)
    print("kolm")
}

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if segue.identifier == "TVtoVCSegue" {
        let otherViewController = segue.destinationViewController as! SecondViewController

        if let cell = sender as? UITableViewCell {
            otherViewController.CurrentClass = cell.textLabel?.text
        }
    }

}

SecondControllerClass.swift

class SecondViewController: UIViewController {

var CurrentClass:String!
override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view.
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

Answer 3

Here is the SecondviewController that receives the passed data:

class TTDetailCntr: UIViewController {
    @IBOutlet var ClassIDLbl: UILabel!
    @IBOutlet var TeacherIDlbl: UILabel!

    var CurrentClass = ""

    override func viewDidLoad() {
        super.viewDidLoad()
        ClassIDLbl.text = CurrentClass

    }