通过展开segue发送数据

Question

我试图通过unwind segue传递信息。我有一个自定义表视图，然后我点击它，它将segue展开到上一个segue。

  func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {

        let indexPath = self.selectedIndex
        self.performSegue(withIdentifier: "SwapBack", sender: indexPath)
  }

但是当我解开segue时，我也希望能够将数据传递给前一个视图控制器：

 override func prepare(for segue: UIStoryboardSegue, sender: Any?) {

            if let indexPath = sender as? IndexPath {
                let vc = segue.destination as! PopUpViewController
                let post = self.posts[indexPath.row] as! [String: AnyObject]
                let Booked = post["title"] as? String
                let Authors = post["Author"] as? String
                let Prices = post["Price"] as? String
                let imageNames = post["image"] as? String
                self.Booked = Booked
                self.Authors = Authors
                self.imageNames = imageNames
                self.Prices = Prices
                vc.SelectABook.isHidden = true
                vc.SelectBookButton.backgroundColor = UIColor.clear

                print("Is this working?")
            }
 }

在目的地segue。这是启动展开segue的原始函数

 @IBAction func Swap (_ sender: UIStoryboardSegue) {

        if sender.source is SwapViewController{
            if let senderVC = sender.source as? SwapViewController{

                self.SwapTitle.text = senderVC.Booked
                self.SwapTax.text = "$0.50"
                self.SwapPrice.text = senderVC.Prices

                if let stringImage = senderVC.imageNames {

                    let imageRef = storage.reference(forURL: "gs://gsignme-14416.appspot.com/images/\(stringImage)")

                    imageRef.data(withMaxSize: 25 * 1024 * 1024, completion: { (data, error) -> Void in
                        if error == nil {
                            self.SwapBook.image = UIImage(data: data!)

                        }else {
                            print("Error downloading image:" )
                        }
                    })
                }
            }
        }
    }

然而，当我解开segue时，没有传递任何数据。我在override func中放了一个print语句，但print语句没有打印，所以我不知道为什么override func没有被调用，我不知道我做错了什么。

这是截图