fatal error: Index out of range, when passing FirebaseData to tablviewCell

Question

所以我正在做一个食物清单项目，我想将 mealname/mealpic/mealDescription 从 FirebaseDatabase 传递到我的 tableViewCell。

它看起来像这样enter image description here

这是我的 FirebaesDatabase 结构

enter image description here

这是我在视图控制器中的代码

    override func viewDidLoad() {
    super.viewDidLoad()

    WeekMenu.delegate = self
    WeekMenu.dataSource = self

    let url = GIDSignIn.sharedInstance().currentUser.profile.imageURL(withDimension: 100)
    let data = try? Data(contentsOf: url!)
    userpic.image = UIImage(data:data!)



    DataService.ds.REF_MENUDATA.observe(.value, with: { (snapshot) in
        if let snapshot = snapshot.children.allObjects as? [FIRDataSnapshot]

        {
            for snap in snapshot {
                print("SNAP: \(snap)")
                if let menuDict = snap.value as? Dictionary<String, AnyObject> {
                    let date = snap.key
                    let menu = menuContnet(weekmenudate: date, menuData: menuDict as! Dictionary<String, String>)
                    self.menus.append(menu)
                }
            }
        }
    })
    self.WeekMenu.reloadData()
}
func numberOfSections(in tableView: UITableView) -> Int {
    return 1
}

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return 5
}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let menu = menus [indexPath.row]
    if let cell: WeekMenu = tableView.dequeueReusableCell(withIdentifier: "WeekMenu") as! WeekMenu {
  cell.configureCell(menu: menu)
    return cell
    }  
}

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

它在运行时崩溃并在第 let menu = menus [indexPath.row]

行抛出 "Index out of range" 错误

我知道这个索引超出范围错误问题是一种常见问题解答但我自己做了一些研究，他们并没有真正帮助

谁能指出哪里出了问题？谢谢

更新

现在我成功地将我在 FirebaseDatabase 中的内容传递到我的表视图中。

但是我从第 1 天到第 5 天有 5 个节点，但我的表视图只显示一个（第 3 天）

在我的 func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int { return menus.count }

为什么会这样？

我的class的内容是这样的

class menuContnet {


private var _menuKey: String!
private var _mealDes : String!
private var _mealPic : String!
private var _mealname : String!
private var _menuRef: FIRDatabaseReference!


var menuKey: String{
    return _menuKey
}

var mealDes : String {
    return _mealDes
}

var mealname : String {
    return _mealname
}

var mealPic : String {
    return _mealPic
}

init (mealDes: String, mealname: String, mealPic: String) {
    self._mealDes = mealDes
    self._mealname = mealname
    self._mealPic = mealPic
}

init (menuKey: String, menuData : Dictionary <String, String>) {
    self._menuKey = menuKey

    if let mealname = menuData["mealname"]  {
        self._mealname = mealname
    }

    if let mealPic = menuData["mealPic"] {
        self._mealPic = mealPic
    }

    if let mealDes = menuData["mealDes"] {
        self._mealDes = mealDes
    }

    _menuRef = DataService.ds.REF_MENUS.child(_menuKey)

}

}

更新

if let snapshot = snapshot.children.allObjects as? [FIRDataSnapshot]            
        {
            for snap in snapshot {

                print ("SNAP: \(snap.key)")

                if  let menuDict = snap.value as? Dictionary<String, String> {
                    let key = snap.key
                    let menu = menuContnet(menuKey: key, menuData: menuDict)
                    print (key)
                    self.menus.append(menu)

                    self.WeekMenu.reloadData()

所以在打印时 ("SNAP: (snap.key)") 我得到了从第 1 天到第 5 天的所有节点

但在打印（关键）时我只得到第 3 天

我认为 "if let menuDict" 语句导致了问题

如果我摆脱 "if" 并使我的代码看起来像这样

                    let menuDict = snap.value as? Dictionary<String, String> 
                    let key = snap.key
                    let menu = menuContnet(menuKey: key, menuData: menuDict)
                    print (key)
                    self.menus.append(menu)

                    self.WeekMenu.reloadData()

它在运行时崩溃并抛出 "unexpectedly found nil while unwrapping an Optional value" 错误

我想我快到了，我会继续做更多的研究

感谢任何提示

Answer 1

尝试：-

DataService.ds.REF_MENUDATA.observe(.value, with: { (snapshot) in
    if let snapshot = snapshot.children.allObjects as? [FIRDataSnapshot]

    {
        for snap in snapshot {
            print("SNAP: \(snap)")
            if let menuDict = snap.value as? Dictionary<String, AnyObject> {
                let date = snap.key
                let menu = menuContnet(weekmenudate: date, menuData: menuDict as! Dictionary<String, String>)
                self.menus.append(menu)
                self.WeekMenu.reloadData()  // This will reload your table to show your newly appended cell one at a time.
            }
     /*

          if menus.count == snap.childrenCount {
                self.WeekMenu.reloadData()     //Will only reload your table after your entire requested database has been retrieved
                 }
     */
        }
    }
})

并更改您的 :-

  func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
      return menus.count ?? 0
    }

fatal error: Index out of range, when passing FirebaseData to tablviewCell

fatal error: Index out of range, when passing FirebaseData to tablviewCell

xcode

firebase

swift

firebase-realtime-database

indexpath