Question

我有一个带有容器视图的视图控制器，该容器视图包含一个静态UITableViewController作为菜单。父视图控制器是UIPageViewController的一部分。

每当用户单击行时，我都想调用一个函数来从PageViewController执行segue。为此，我在didSelectRowAt内添加了MenuTableViewController。 -由于正在执行打印请求，因此此功能工作正常。

要从PageViewController调用函数，我尝试使用委托，但不知何故该函数将无法执行。

RootPageViewController：

override func viewDidLoad() {
        super.viewDidLoad()
        self.dataSource = self

        let vc = storyboard?.instantiateViewController(withIdentifier: "menuView") as! MenuTableViewController
        vc.delegate = self
        ...

}

func goToMap() {
        performSegue(withIdentifier: "goMap", sender: self)
}

MenuTableViewController：

class MenuTableViewController: UITableViewController {

    let defaults = UserDefaults.standard

    weak var delegate: RootPageViewController?
}

extension MenuTableViewController {

    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        print(indexPath.row)

        if indexPath.row == 2 {
            delegate?.goToMap()
        }

        tableView.deselectRow(at: indexPath, animated: true)
    }

}

编辑：在PageViewController的viewDidLoad（）中

let home = storyboard?.instantiateViewController(withIdentifier: "homeView") as! HomeViewController
home.loadViewIfNeeded()
let menu = home.children[1] as! MenuTableViewController
print("Children:", home.children)
menu.delegate = self

class RootPageViewController: UIPageViewController, UIPageViewControllerDataSource, UIScrollViewDelegate, UIViewControllerTransitioningDelegate {

    lazy var viewControllerList:[UIViewController] = {

            let sb = UIStoryboard(name: "Main", bundle: nil)

            let vc1 = sb.instantiateViewController(withIdentifier: "homeView")
            let vc2 = sb.instantiateViewController(withIdentifier: "timelineView")

            return [vc1, vc2]

    }()

    let defaults = UserDefaults.standard
    let transition = CircularTransition()

    override func viewDidLoad() {
        super.viewDidLoad()
        self.dataSource = self

        let home = storyboard?.instantiateViewController(withIdentifier: "homeView") as! HomeViewController
        home.delegate = self
        print(home.delegate)

        if let secondViewController = viewControllerList.first as? HomeViewController {
            self.setViewControllers([secondViewController], direction: .forward, animated: true, completion: nil)
....

Answer 1

您为menuVc创建另一个对象，并为其分配委托，它不同于情节提要中的1，因此在PagerVC的viewDidLoad内部

let home = //
let menu = home.children.first as! MenuTableViewController
menu.delegate = self

Answer 2

这是您应该使用委托的方式：
MenuTableViewController

protocol MenuTableViewControllerDelegate: class {
    func menuTableViewController(menuTableViewController: MenuTableViewController, shouldGoToMap: Bool)
}

class MenuTableViewController: UITableViewController {

    let defaults = UserDefaults.standard

    weak var delegate: MenuTableViewControllerDelegate?

    ...
}

extension MenuTableViewController {

    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        print(indexPath.row)

        if indexPath.row == 2 {
            delegate?.menuTableViewController(menuTableViewController: self, shouldGoToMap: true)
        }

        tableView.deselectRow(at: indexPath, animated: true)
    }

}

RootPageViewController

class RootPageViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        self.dataSource = self

        let vc = storyboard?.instantiateViewController(withIdentifier: "menuView") as! MenuTableViewController
        vc.delegate = self

    }

    func goToMap() {
        performSegue(withIdentifier: "goMap", sender: self)
    }
}

extension RootPageViewController: MenuTableViewControllerDelegate {
    func menuTableViewController(menuTableViewController: MenuTableViewController, shouldGoToMap: Bool) {
        goToMap()
    }
}

委托将不执行功能

2 个答案: