swift - How to make delegate between a cell with a UIView and a view controller?

Question

I have a view controller which holds a tableview. Inside that tableview I have a dynamic cell. Inside of that cell I have a UIView. Inside the UIView I have a label with a tap recognizer which is supposed to perform a segue to a different view controller. I have tried making a delegate between the view controller by putting vc.delegate = self in the viewdidload, but it did not work. I have also tried putting the same line inside cellforrowat, but it still doesn't do anything. How can I make a delegate that communicates from my cell with UIView to this view controller? Also, the thing that will be communicating is my UIView class and not my cell class.

标签： swift

Answer 1

If I understand it correctly. Create a delegate protocol for your cell view, put delegate property to the cell and pass it via the tableView method tableView(_:cellForRowAt:) to the controller.

Protocol implementation:

protocol MyCellViewDelegate: class {
    func viewDidTap(_ view: MyCellView)
}

Cell View Implementaiton:

class MyCellView: UIView {

    private let tapGesture = UITapGestureRecognizer()
    weak var delegate: MyCellViewDelegate?
        
    override init(frame: CGRect) {
        super.init(frame: frame)
        
        tapGesture.addTarget(self, action: #selector (viewDidTap))
    }
    
    @objc
    func viewDidTap() {
        delegate?.viewDidTap(self)
    }
}

Cell Implementation:

Then, in your Cell implementation. Pass the delegate reference to the MyCellView, which will be handled in the Controller.

class MyCell: UITableViewCell {
    
    private let myContentView = MyCellView()
    
    weak var delegate: MyCellViewDelegate? {
        didSet { myContentView.delegate = delegate }
    }
    
    required init?(coder: NSCoder) { fatalError("init(coder:) has not been implemented") }
    override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
        super.init(style: style, reuseIdentifier: reuseIdentifier)
    }
}

Then you should be able to set delegate in the TableView DataSource delegate methods.

Controller Implementation:

extension MyController: UITableViewDataSource {
    
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        // Dequeue the cell...
        cell.delegate = self
        return cell
    }
}

And it will force you to add delegates.

extension MyController: MyCellViewDelegate {
    
    func viewDidTap(_ view: MyCellView) {
        // Do some stuff
    }
}

However, TableView could "steal" your Tap Gesture action. Maybe, if you set tableView.isUserInteractionEnabled = false, it could work.