Question

我制作了一个包含折叠单元格的表视图，我跟着这个tutorial;一切都很好，除了segue方法。我只是尝试添加performsegueWithIdentifier方法（通过单元格在故事板中添加segue）

func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath)
    {           
        performSegueWithIdentifier("toChantController", sender: self)
    }

和prepareForSegue方法：

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?)
    {
        if segue.identifier == "toChantController"
        {
            let indexPath = tableView.indexPathForCell(sender as! UITableViewCell)
            let controller = segue.destinationViewController as! ChantViewController
            controller.chant = "\(sections[indexPath!.row])"
        }
    }

但Xcode向我发送此错误

“无法将'iSupporters.TeamChantViewController'类型的值（0x104562730）转换为'UITableViewCell'（0x106600540）。”

全班同学：

import UIKit

class TeamChantViewController: UIViewController, UITableViewDataSource, UITableViewDelegate
{
    // MARK: properties

    var teamChants: TeamModel!
    @IBOutlet weak var tableView: UITableView!

    struct Section {
        var name: String!
        var items: [String]!
        var collapsed: Bool!

        init(name: String, items: [String], collapsed: Bool = true) {
            self.name = name
            self.items = items
            self.collapsed = collapsed
        }
    }

    var sections = [Section]()

    override func viewDidLoad()
    {
        super.viewDidLoad()

        tableView.backgroundColor = UIColor.clearColor()
        tableView.separatorColor = UIColor.clearColor()

        sections = [
            Section(name: "Juventus", items: ["Olè", "fino alla fine", "ovunque voi giocate", "juve olè"]),
            Section(name: "Derby", items: ["toro merda", "odio i granata", "il viola è il colore che odio"]),
            Section(name: "Giocatori", items: ["Vidal", "Pogba", "Del Piero"])
        ]
    }

    override func viewWillAppear(animated: Bool)
    {
        super.viewWillAppear(animated)
        self.tabBarController?.tabBar.hidden = true
    }

    // MARK: collection view data source and delegate

    func numberOfSectionsInTableView(tableView: UITableView) -> Int
    {
        return 1
    }

    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int
    {
        var count = sections.count

        for section in sections
        {
            count += section.items.count
        }

        return count
    }

    func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat
    {
        let section = getSectionIndex(indexPath.row)
        let row = getRowIndex(indexPath.row)

        if row == 0 {
            return 50.0
        }

        return sections[section].collapsed! ? 0 : 44.0
    }

    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
    {
        let section = getSectionIndex(indexPath.row)
        let row = getRowIndex(indexPath.row)

        if row == 0
        {
            let cell = tableView.dequeueReusableCellWithIdentifier("teamChantsHeader") as! TeamChantsHeader
            cell.teamChantSectionTitle.text = sections[section].name
            cell.toggleButton.tag = section
            cell.toggleButton.setTitle(sections[section].collapsed! ? "+" : "-", forState: .Normal)
            cell.toggleButton.addTarget(self, action: #selector(TeamChantViewController.toggleCollapse), forControlEvents: .TouchUpInside)

            return cell
        } else {
            let cell = tableView.dequeueReusableCellWithIdentifier("teamChantsCell") as UITableViewCell!
            cell.textLabel?.text = sections[section].items[row - 1]

            return cell
        }
    }

    func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath)
    {
        performSegueWithIdentifier("toChantController", sender: self)
        print(self)
    }

    // MARK: navigation (segue)

    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?)
    {
        if segue.identifier == "toChantController"
        {
            let indexPath = tableView.indexPathForCell(sender as! UITableViewCell)
            let controller = segue.destinationViewController as! ChantViewController
            controller.chant = "\(sections[indexPath!.row])"
        }
    }

    // MARK: - other methods

    func toggleCollapse(sender: UIButton)
    {
        let section = sender.tag
        let collapsed = sections[section].collapsed

        // Toggle collapse
        sections[section].collapsed = !collapsed

        let indices = getHeaderIndices()

        let start = indices[section]
        let end = start + sections[section].items.count

        tableView.beginUpdates()
        for i in start ..< end + 1
        {
            tableView.reloadRowsAtIndexPaths([NSIndexPath(forRow: i, inSection: 0)], withRowAnimation: .Automatic)
        }
        tableView.endUpdates()
    }

    func getSectionIndex(row: NSInteger) -> Int
    {
        let indices = getHeaderIndices()

        for i in 0..<indices.count
        {
            if i == indices.count - 1 || row < indices[i + 1]
            {
                return i
            }
        }

        return -1
    }

    func getRowIndex(row: NSInteger) -> Int
    {
        var index = row
        let indices = getHeaderIndices()

        for i in 0..<indices.count
        {
            if i == indices.count - 1 || row < indices[i + 1]
            {
                index -= indices[i]
                break
            }
        }

        return index
    }

    func getHeaderIndices() -> [Int]
    {
        var index = 0
        var indices: [Int] = []

        for section in sections
        {
            indices.append(index)
            index += section.items.count + 1
        }

        return indices
    }
}

有人可以帮助我执行这个赛段吗？

编辑：我在故事板中的segue

Answer 1

你在这做两件事，

首先，您已在UITableViewCell到ChantViewController的stroyboard中创建了segue。
现在didSelectRowAtIndexPath您正在再次执行segue，并将self作为TeamChantViewController的参考。

你需要改变任何一件事来解决你的问题。

编辑：根据您的评论，您需要在此sender方法中使用performSegue参数传递indexPath对象，并在prePareForSegue方法中获取该indexPath。 / p>

func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {           
    performSegueWithIdentifier("toChantController", sender: indexPath)
} 

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if segue.identifier == "toChantController"
    {
        let indexPath = sender as! NSIndexPath
        let controller = segue.destinationViewController as! ChantViewController
        controller.chant = "\(sections[indexPath!.row])"
    }
}

触发来自“折叠”单元格的segue

1 个答案: