将 Firebase 数据从 View Controller 发送到 View Controller

Question

我目前在名为MainViewController 的 ViewController 中有一个 UITableView，它从 Firebase 数据库加载我的所有内容。我还有另一个名为 DetailsViewController 的 ViewController，它从通过 segue 单击的任何单元格加载数据。我要做的是创建另一个名为 CommentViewController 的 ViewController 并从之前单击的同一单元格加载信息（Segue 来自 DetailsViewController）。

这就是我目前的 Storyboard 设置方式：

这就是我目前将数据从MainViewController 加载到DetailsViewController 的方式

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        performSegue(withIdentifier: "showDetails", sender: self)
}

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.identifier == "showDetails" {
        if let indexPath = self.postsTableView.indexPathForSelectedRow {
            let post = posts[indexPath.row] as! [String: AnyObject]
            let postDetails = post["postID"] as? String
            let controller = segue.destination as! DetailsViewController
            controller.postDetails = postDetails
        }
    }
}

// DetailsViewController
var postDetails: String?

override func viewDidLoad() {
    super.viewDidLoad()
    FIRDatabase.database().reference().child("posts").child(postDetails!).observeSingleEvent(of: .value, with: { (snapshot) in
        if let dictionary = snapshot.value as? [String: AnyObject] {
            self.title = dictionary["title"] as? String
            self.priceLabel.text = dictionary["price"] as? String
            self.ratingLabel.text = dictionary["rating"] as? String
            self.usernameLabel.text = dictionary["username"] as? String
            self.detailsTextView.text = dictionary["description"] as? String
         }
    })
}

我怎样才能以最简单和最简单的方式传递这些数据？

Answer 1

您需要在主控制器的表中加载数据 didselect 方法并将字典传递给 detailsController 并为所有插座赋值。见下面代码

MainController

 var dictDetails: [String:AnyObject]?
.
.
.
.
.



 func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
            let post = posts[indexPath.row] as! [String: AnyObject]
                let postDetails = post["postID"] as? StringFIRDatabase.database().reference().child("posts").child(postDetails!).observeSingleEvent(of: .value, with: { (snapshot) in
            if let dictionary = snapshot.value as? [String: AnyObject] {
                  self.dictDetails = dictionary
                  performSegue(withIdentifier: "showDetails", sender: self)
             }
        })

    }

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if segue.identifier == "showDetails" {

                let controller = segue.destination as! DetailsViewController
                controller.dictionary = self.dictDetails

        }
    }

    // DetailsViewController
    var dictionary: [String:AnyObject]?

    override func viewDidLoad() {
        super.viewDidLoad()
        self.title = self.dictionary["title"] as? String
                self.priceLabel.text = self.dictionary["price"] as? String
                self.ratingLabel.text = self.dictionary["rating"] as? String
                self.usernameLabel.text = self.dictionary["username"] as? String
                self.detailsTextView.text = self.dictionary["description"] as? String

    }

需要在mainController中取dictDetails字典。

Answer 2

根据 sschunara 的回答，让我为您的回答添加额外的代码。

您的DetailViewController's 字典中有所有详细信息

// DetailsViewController
    var dictionary: [String:AnyObject]?

    override func viewDidLoad() {
        super.viewDidLoad()
        self.title = self.dictionary["title"] as? String
                self.priceLabel.text = self.dictionary["price"] as? String
                self.ratingLabel.text = self.dictionary["rating"] as? String
                self.usernameLabel.text = self.dictionary["username"] as? String
                self.detailsTextView.text = self.dictionary["description"] as? String

    }

同样，您必须传递与MainViewController-> Detail ViewController 相同的数据

现在DetailViewController -> CommentViewController

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if segue.identifier == "showComments" {

            let controller = segue.destination as! CommentViewController
            controller.dictionary = self.dictDetails

    }
}

根据您的要求传递整个字典或仅注释字符串，您可以在CommnetsViewController 中访问它并将该数据设置为lable。

希望这将清除您的数据传递概念。