如何在 TableView Cell 中创建长按按钮以进行 segue

Question

I can only create my segue function from the ViewController and I must have the longPress functions in my TableViewCell. There's no way to make reference to the segue function without getting an error. How would I implement this code in the cellForRow to segue when the button is held within the TableView Cell? By the way, I'm using a storyboard.

@objc func longPress(gesture: UILongPressGestureRecognizer) {
        if gesture.state == UIGestureRecognizer.State.began {
            print("Long Press")
            //performSegue(withIdentifier: "toProfile", sender: self)
        }
      }

    func addLongPressGesture(){
        let longPress = UILongPressGestureRecognizer(target: self, action: #selector(longPress(gesture:)))
            longPress.minimumPressDuration = 0.75
            self.expandButton.addGestureRecognizer(longPress)

Answer 1

I found an easy yet unorthodox solution but works like a charm:

Place a second button into your TableView Cell, connect your segue, and set it to hidden. Then create your IBOutlet for it, which I named SegueButton:

@IBOutlet weak var LongPressButton: UIButton!
@IBOutlet weak var SegueButton: UIButton!

Now add to your awakeFromNib:

override func awakeFromNib() {
addLongPressGesture()
}

Lastly, add the long press button code:

@objc func longPress(gesture: UILongPressGestureRecognizer) {
            if gesture.state == UIGestureRecognizer.State.began {
                print("Segue was Successful")
                SegueButton.sendActions(for: .touchUpInside)
                }
            }

    func addLongPressGesture(){
    let longPress = UILongPressGestureRecognizer(target: self, action: #selector(longPress(gesture:)))
        longPress.minimumPressDuration = 0.75
        self.LongPressButton.addGestureRecognizer(longPress)
    }
}

Answer 2

You need a way to communicate from your button / cell back to your view controller. I suggest using a closure. It would look something like this (I haven't tested this code)...

class SomeCell: UITableViewCell {

    var didLongPress: (()->Void)? = nil

    @objc func longPress(gesture: UILongPressGestureRecognizer) {
        if gesture.state == UIGestureRecognizer.State.began {
            didLongPress?() 
        }
    }

    override func prepareForReuse() {
        didLongPress = nil
    }
}

class TableViewController: UITableViewController {

    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "CellId") as! SomeCell
        cell.didLongPress = { [weak self] in 
            self?.performSegue(withIdentifier: "showDetail", sender: nil)
        }
        return cell
    }

}

Answer 3

I set up the button inside the tableview cell to segue to one view controller when tapped and a different one when long pressed.

1) Create a delegate protocol. You can put this in the custom TableViewCell class file but not within the class itself.

protocol MyTableViewCellDelegate : class {
   func didTapButton ()
   func didLongPressButton ()
}

2) Inside the actual TableViewCell class, put the following:

weak var delegate: MyTableViewCellDelegate?

// Boilerplate code

@objc func didLongPress(sender: UILongPressGestureRecognizer) {
    if sender.state == UIGestureRecognizer.State.began {
        delegate?.didLongPressButton()
    }
}

Control drag your button from your tableview cell into this file. Then add the additional logic.

@IBAction func expandButton(_ sender: Any) {
    let longPress = UILongPressGestureRecognizer(target: self, action: #selector(didLongPress))
    self.addGestureRecognizer(longPress)
    delegate?.didTapButton()        
}

In your main ViewController file, inside cellForRowAt:

cell.delegate = self

Then somewhere outside the ViewController's class logic, add the following to conform to your delegate protocol and perform your segues:

extension ViewController: MyTableViewCellDelegate {
    func didTapButton() {
        performSegue(withIdentifier: "toInfoSegue", sender: self)
}
    @objc func didLongPressButton() {
        performSegue(withIdentifier: "toProfileSegue", sender: self)
    }
}