ios - Swift 4 准备(用于 segue :) not being called

Question

我有一个 Split View Controller ，当我单击 TableView 中的项目时，它不会调用我的 prepare(for segue:) 方法。这是我的 prepare(for segue:) 方法:

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        print("Here");
        if segue.identifier == "showPOsDetail" {
            if let indexPath = tableView.indexPathForSelectedRow {
                let object = objects[indexPath.row] as! NSDate
                let controller = (segue.destination as! UINavigationController).topViewController as! POsDetail
                controller.detailItem = object
                controller.navigationItem.leftBarButtonItem = splitViewController?.displayModeButtonItem
                controller.navigationItem.leftItemsSupplementBackButton = true
            }
        }
    }

这是我的 Storyboard的截图。我不知道为什么没有调用此方法。

几天来我一直在尝试用 out 计算，我对它不起作用感到非常沮丧。

这是我的完整主 Controller :

import UIKit

class POsMaster: UITableViewController {

    var POsDetailController: POsDetail? = nil
    var objects = [Any]()


    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view, typically from a nib.
        navigationItem.leftBarButtonItem = editButtonItem

        let addButton = UIBarButtonItem(barButtonSystemItem: .add, target: self, action: #selector(insertNewObject(_:)))
        navigationItem.rightBarButtonItem = addButton
        if let split = splitViewController {
            let controllers = split.viewControllers
            POsDetailController = (controllers[controllers.count-1] as! UINavigationController).topViewController as? POsDetail
        }

    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    @objc
    func insertNewObject(_ sender: Any) {
        objects.insert(NSDate(), at: 0)
        let indexPath = IndexPath(row: 0, section: 0)
        tableView.insertRows(at: [indexPath], with: .automatic)
    }

    // MARK: - Segues

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        print("Here");
        if segue.identifier == "showPOsDetail" {
            if let indexPath = tableView.indexPathForSelectedRow {
                let object = objects[indexPath.row] as! NSDate
                let controller = (segue.destination as! UINavigationController).topViewController as! POsDetail
                controller.detailItem = object
                controller.navigationItem.leftBarButtonItem = splitViewController?.displayModeButtonItem
                controller.navigationItem.leftItemsSupplementBackButton = true
            }
        }
    }

    // MARK: - Table View

    override func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return objects.count
    }

    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "POCell", for: indexPath)

        let object = objects[indexPath.row] as! NSDate
        cell.textLabel!.text = object.description
        return cell
    }

    override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
        // Return false if you do not want the specified item to be editable.
        return true
    }

    override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
        if editingStyle == .delete {
            objects.remove(at: indexPath.row)
            tableView.deleteRows(at: [indexPath], with: .fade)
        } else if editingStyle == .insert {
            // Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view.
        }
    }


}

Answer 1

当您在 Storyboard中连接您的 segue 时，会打开一个弹出窗口，您必须检查您是否已从 Selection 组 而不是 Accessory 组 设置您的 segue， Selection group 连接将调用您的 prepareForSegue: 方法。