When I Add Checklist, the Cancel And Done button is ok, I can add Checklist or Cancel.
When I press accessory button to Edit Checklist screen, I can edit Checklist, but the Cancel And Done buttons don’t have any response, I can’t close the screen or save the Checklist.
I debug the codes, I find the delegate? is nil, I don’t know why?
import UIKit
protocol ListDetailViewControllerDelegate: class {
func listDetailViewControllerDidCancel(
_ controller: ListDetailViewController)
func listDetailViewController(_ controller: ListDetailViewController,
didFinishAdding checklist: Checklist)
func listDetailViewController(_ controller: ListDetailViewController,
didFinishEditing checklist: Checklist)
}
class ListDetailViewController: UITableViewController, UITextFieldDelegate {
@IBOutlet weak var doneBarButton: UIBarButtonItem!
@IBOutlet weak var textField: UITextField!
weak var delegate: ListDetailViewControllerDelegate?
var checklistToEdit: Checklist?
override func viewDidLoad() {
super.viewDidLoad()
if let checklist = checklistToEdit {
title = "Edit Checklist"
textField.text = checklist.name
doneBarButton.isEnabled = true
}
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
textField.becomeFirstResponder()
}
@IBAction func cancel() {
delegate?.listDetailViewControllerDidCancel(self)
}
@IBAction func done() {
if let checklist = checklistToEdit {
// edit
checklist.name = textField.text!
delegate?.listDetailViewController(self,
didFinishEditing: checklist)
} else {
let checklist = Checklist(name: textField.text!)
delegate?.listDetailViewController(self,didFinishAdding: checklist)
}
}
override func tableView(_ tableView: UITableView,willSelectRowAt indexPath: IndexPath) -> IndexPath? {
return nil
}
func textField(_ textField: UITextField,
shouldChangeCharactersIn range: NSRange,
replacementString string: String) -> Bool {
let oldText = textField.text! as NSString
let newText = oldText.replacingCharacters(in: range, with: string)
as NSString
doneBarButton.isEnabled = (newText.length > 0)
return true
}
}
AllListsViewController
...
func listDetailViewController(_ controller: ListDetailViewController,
didFinishAdding checklist: Checklist) {
let newRowIndex = lists.count
lists.append(checklist)
let indexPath = IndexPath(row: newRowIndex, section: 0)
let indexPaths = [indexPath]
tableView.insertRows(at: indexPaths, with: .automatic)
dismiss(animated: true, completion: nil)
}
func listDetailViewController(_ controller: ListDetailViewController,
didFinishEditing checklist: Checklist) {
if let index = lists.index(of: checklist) {
let indexPath = IndexPath(row: index, section: 0)
if let cell = tableView.cellForRow(at: indexPath) {
cell.textLabel!.text = checklist.name
}
}
dismiss(animated: true, completion: nil)
}
...
override func tableView(_ tableView: UITableView, accessoryButtonTappedForRowWith indexPath: IndexPath) {
let navigationController = storyboard!.instantiateViewController(withIdentifier: "ListDetailNavigationController") as! UINavigationController
let controller = navigationController.topViewController as! ListDetailViewController
let checklist = lists[indexPath.row]
controller.checklistToEdit = checklist
present(navigationController, animated: true, completion: nil)
}
thanks.