Question

我正在尝试使用TableViewController和ViewController之间的segue传递包含“Bar Name”值及其各自“Street Name”的两个字符串值。我使用的是名为HomeController的类，另一个名为BarPage。我为主屏幕准备了以下代码，这是一个表视图控制器保持单元格，单击时，应该执行我已经包含在故事板上的segue。我删除了一些解释这个问题的冗余代码：

import UIKit
import Firebase

class HomeController: UIViewController, UITableViewDelegate, UITableViewDataSource{

    let barsArray = [Data(image: "bar1", street: "123 North Street"),
                    Data(image: "bar2", street: "345 South Street"),
                    Data(image: "bar3", street: "678 West Street")]

    let tableView: UITableView = {
        let tv = UITableView()
        tv.separatorStyle = .none
        tv.allowsSelection = true
        return tv
    }()

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return barsArray.count
    }
    func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
        return 100
    }
    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

        let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! BarCell

        cell.barImageView.image = UIImage(named: barsArray[indexPath.item].image!)
        cell.barCoverLabel.text = "Street: " + barsArray[indexPath.item].street!

        return cell
    }

    var locationName : String?
    var locationStreet : String?

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        let barPage = segue.destination as! BarPage
        barPage.barName = locationName!
        barPage.barStreet = locationStreet!
    }

    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {


        locationName = self.barsArray[indexPath.row].image
        locationStreet = self.barsArray[indexPath.row].street


        // WHEN USER PRESSES A ROW, PERFORM SEGUE

        performSegue(withIdentifier: "mySegue", sender: self)

        // Then enter the second view controller

        present(BarPage(), animated: true, completion: nil)


    }



    override func viewDidLoad() {
        super.viewDidLoad()
        self.tableView.backgroundColor = .black
        setUpTableView()

    }
    func setUpTableView(){
        tableView.dataSource = self
        tableView.delegate = self
        tableView.register(BarCell.self, forCellReuseIdentifier: "cell")

        view.addSubview(tableView)

        .... add anchors and constraints for table view ..........
    }

}

var home: HomeController?

class BarCell: UITableViewCell{


    ... add custom styling for each cell of the table view ....

    override init(style: UITableViewCellStyle, reuseIdentifier: String?){
        super.init(style: style, reuseIdentifier: reuseIdentifier)
        setup()
    }

    func setup(){
        .......... add anchors and constraints for the cell..........
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

以下是View Controller BarPage中应该从他的segue中检索字符串的代码。

import UIKit
import Firebase



class BarPage: UIViewController{

    let homeController = HomeController()

    // These, in theory, should be the variables that retrieve the strings through my segue

    var barName = String()
    var barStreet = String()

    public let barStreet: UILabel = {
        var label = UILabel()
        label.text = "The street is: "// + barStreet
        label.textColor = .black
        label.font = UIFont.boldSystemFont(ofSize: 16)
        return label
    }()
    let barImage: UIImageView = {
        let iv = UIImageView()
        iv.image = UIImage(named: barName) // Should retrieve the image based on the string that is passed
        iv.contentMode = .scaleAspectFill
        iv.backgroundColor = .yellow
        //iv.clipsToBounds = true
        return iv
    }()

    override func viewDidLoad() {
        super.viewDidLoad()
        self.view.backgroundColor = UIColor.mint()

        view.addSubview(barStreet)
        view.addSubview(barImage)

        positionElements()

    }

    func positionElements(){
        .......... add anchors and constraints for the elements..........
    }
}

如果我在不包含segue的情况下运行我的代码，则转换工作正常。但是，如果我包含Segue，我会收到以下错误：

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', 
reason: 'Receiver (<ProjectName.HomeController: 0x7f9fcec0fb10>) has 
no segue with identifier 'mySegue''

如果事实上我的故事板中有一个带有该标识符的segue，那怎么可能呢？这是我的故事板的图片，显示了我正在使用的标识符：

正如您在右侧所看到的，相同的标识符与我的故事板中的segue匹配，但我的错误表明无法找到它。我该如何解决这个问题？这是因为我试图从TableViewController执行Segue吗？对于任何模棱两可的道歉，第一个月成为Swift用户。任何能指出正确方向的提示/建议都会非常有帮助。

Answer 1

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath)  {
                performSegue(withIdentifier: "mySegue", sender: indexPath.row)
            }

Answer 2

在准备segue时添加这样的内容：

    if let selectedIndex = tableView.indexPathForSelectedRow {
        barPage.barStreet = barsArray[selectedIndex.row].street
        ...

}

并确保您正在调用self.performSegue ...

Swift - TableViewController之间的简单Segue期间出错 - ＆gt; ViewControllers

2 个答案: