Question

我想从表视图的选定单元格中检索文本，以在其他视图控制器中修改标签。我的第一个问题是，我无法成功获取值，并将其放置后

这是我的tableview文件：

Foos

我的帖子文件：

class SelectionMarqueViewController: UITableViewController {

    var posts = [Post]()
    var indexMarques = 0
    override func viewDidLoad() {
        super.viewDidLoad()
        tableView.dataSource = self
        loadMarques()
    }

    func loadMarques() {
        var ref : DatabaseReference?
        ref = Database.database(url: "https://myride-test.firebaseio.com/").reference()
        ref?.observe(.childAdded, with: { (snapshot) in
            if let dict = snapshot.value as? [String: Any] {
                let marqueText = dict["Marque"] as! String
                let post = Post(marqueText: marqueText)
                self.posts.append(post)
                //print(self.posts)
                self.tableView.reloadData()
            }
            if let dict = snapshot.value as? [String: Any] {
                let marqueText = dict["Marque"] as! String
                let post = Post(marqueText: marqueText)
                self.posts.append(post)
                self.posts = Array(Set(self.posts))
                self.tableView.reloadData()
            }
        })      
    }

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

    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "PostCell", for: indexPath)
        let orderPosts = self.posts.sorted { $0.marque < $1.marque}
        cell.textLabel?.text = orderPosts[indexPath.row].marque
        return cell
    }

    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        indexMarques = indexPath.row
    }

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        var selectionMarque = segue.destination as! ChoiceGeneralTableViewController
    }      
}

然后在我的视图文件中必须更改标签：

class Post : Hashable {
    var marque: String

    init(marqueText: String) {
        marque = marqueText
    }
    // Equatable for contains
    static func == (lhs:Post,rhs:Post) -> Bool {
        return lhs.marque == rhs.marque
    }
    // Hashable for Set
    var hashValue:Int {
        return marque.hashValue
    }
}

实际上我没有成功检索单元格的文本，self.posts返回ProjectName.Post

感谢您的研究和帮助！

Answer 1

向ChoiceGeneralTableviewController添加变量：

public var postText: String?

实例化selectionMarque（另一个表视图控制器）后，立即在表视图文件（第一个）didSelectRowAtIndexPath（...）中：

selectionMarque.postText = orderPosts[indexMarques].marque

在ChoiceGeneralTableviewController中，您可以访问postText作为标签的文本。

编辑：代码

class SelectionMarqueViewController: UITableViewController {

    var posts = [Post]()
    var indexMarques = 0

    override func viewDidLoad() {
        super.viewDidLoad()
        tableView.dataSource = self
        loadMarques()
    }

    func loadMarques() {
        var ref : DatabaseReference?
        ref = Database.database(url: "https://myride-test.firebaseio.com/").reference()
        ref?.observe(.childAdded, with: { (snapshot) in
            if let dict = snapshot.value as? [String: Any] {
                let marqueText = dict["Marque"] as! String
                let post = Post(marqueText: marqueText)
                self.posts.append(post)
                //print(self.posts)
                self.tableView.reloadData()
            }
            if let dict = snapshot.value as? [String: Any] {
                let marqueText = dict["Marque"] as! String
                let post = Post(marqueText: marqueText)
                self.posts.append(post)
                self.posts = Array(Set(self.posts))
                self.tableView.reloadData()
            }
        })

        // Sort the posts
        self.posts = self.posts.sorted { $0.marque < $1.marque}
    }

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

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

        cell.textLabel?.text = self.posts[indexPath.row].marque
        return cell
    }

    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        indexMarques = indexPath.row
    }

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        var selectionMarque = segue.destination as! ChoiceGeneralTableViewController
        selectionMarque.postText = posts[indexMarques].marque
    }
}

和目标视图控制器：

class ChoiceGeneralTableViewController: UITableViewController {
    @IBOutlet weak var marquePressed: UILabel!
    @IBOutlet weak var labelMarque: UILabel!

    public var postText: String?

    var marqueSelected = posts[indexMarques]
    override func viewDidLoad() {
        super.viewDidLoad()
        // Make sure postText is not nil
        if let text = postText {
            labelMarque.text = text
        }
    }
}

Answer 2

您可以使用tableView.indexPath(for:)方法获取发件人索引路径

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    let indexPath = tableView.indexPath(for: sender as UITableViewCell);

    var selectionMarque = segue.destination as! ChoiceGeneralTableViewController
    selectionMarque.selected = orderPosts[indexPath.row]
}

然后，您需要将posts[indexMarques]更改为: Post!，因为该类无权访问posts数组，我们需要直接传递所选的Post对象。

class ChoiceGeneralTableViewController: UITableViewController {
    @IBOutlet weak var marquePressed: UILabel!
    @IBOutlet weak var labelMarque: UILabel!

    var selected: Post!
    override func viewDidLoad() {
        super.viewDidLoad()
        labelMarque.text = selected.marque
    }
}

如何从选定的Tableview单元格检索文本？

2 个答案: