ios - Segue 没有将值从我的 StoriesTableViewController 传递到 SingleArtCallViewController。为什么会这样？

Question

如果用户单击我的 StoriesTableViewController 中的表项，我需要将 id 的值传递给 SingleArtCallViewController，以便 SingleArtCallViewController 可以显示适当的详细信息。

问题是，如果我打印用户按下的项目的 ID，它会正确打印它。但它没有被其他 ViewController 接收到。有人可以为我解决这个问题吗？

故事 TableView Controller :

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

    finalId = idTable[myIndex]

    let story = stories[indexPath.row]
    ArtcallID = story.id


   performSegue(withIdentifier: "singleArtcall", sender: self)
}

   override func prepare(for segue: UIStoryboardSegue, sender: Any?) {


print(ArtcallID + "is the index of the item that was selected")
   //this correctly prints the id
let id = segue.destination as! SingleArtcallViewController
    id.ArtcallID = ArtcallID
 //  print("id: ",id)

   }

SingleArtCallViewController:

var ArtcallID: String!

    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)

        print("ArtcallID: ", ArtcallID)

        //If I print this I"m getting the result "ArtcallID:  some("")"


    }

故事.swift:

import Firebase

class Story
{
    var id: String = ""
    var text: String = ""
    var numberOfLikes = 0
    var numberOfAngry = 0
    let ref: DatabaseReference!
    var fundedAmt: Int = 0
    var targetAmt: Int = 0
    var perfCity: String = ""
    var targetDate: IntMax = 0
    var backers: Int = 0
    var fundedPercent: Int = 0
    var imageURL: String = ""

    init(text: String) {
        self.text = text
        ref = Database.database().reference().child("Fund").childByAutoId()
    }

    init(snapshot: DataSnapshot)
    {
        ref = snapshot.ref
        if let value = snapshot.value as? [String : Any] {
            text = value["artist_name"] as! String
            backers = value["total_backers"] as! Int
            perfCity = value["perf_location"] as! String
            fundedAmt = value["amount_funded"] as! Int
            targetAmt = value["target_amount"] as! Int
            fundedPercent = value["percent_funded"] as! Int

          //  numberOfLikes = value["numberOfLikes"] as! Int
          //  numberOfAngry = value["numberOfAngry"] as! Int
            id = snapshot.key
        }
    }

Answer 1

如果我正确理解您要实现的目标，并且您通过控制从原型(prototype)单元格拖动到 SingleArtcallViewController 创建了 segue:

代码不起作用的具体原因是 prepare(for segue:...) 比 tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) 运行得早。此外，您运行 prepare for segue 两次。

如果是这样，你不需要这个方法

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

只需使用 prepare(for segue:...):

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    guard let selectedRow = tableView.indexPathForSelectedRow?.row,
        let vc = segue.destination as? SingleArtcallViewController else {return}
    vc.artCallId = stories[selectedRow].id
}