無法從Firebase正確檢索數據

Question

這是我試圖從Firebase檢索代碼並對其執行操作的第二個版本。這是我如何做它的第二種方式：

channelRef?.observe(.childChanged, with: { (snapshot) -> Void in 
     let update = snapshot.value as! Dictionary<String, AnyObject> 
     var readyToGoValue: Bool? 
     var userID: String? 
     var amountOfPlayers: Int? 
     var changedCreator: String? 
     if let updatedReadyToGo = update["readyToGo"] as! Bool!{ 
      if updatedReadyToGo == true 
      { 
       readyToGoValue = true 
      } 
      else 
      { 
       readyToGoValue = false 
      } 
     } 
     if let updateduserID = update["userID"] as! String!{ 
      userID = updateduserID 
     } 
     if let updatedAmountOfPlayers = update["currentPlayers"] as! Int!{ 
      amountOfPlayers = updatedAmountOfPlayers 
     } 
     if let updateduserID = update["userID"] as! String!{ 
      userID = updateduserID 
     } 
     if let updatedCreator = update["creator"] as! String!{ 
      changedCreator = updatedCreator 
     } 

     let currentUser = FIRAuth.auth()?.currentUser?.uid 

     if changedCreator != nil 
     { 
      print("changed creator") 
      self.creator = changedCreator! 
     } 

這開車撞錯誤代碼：

無法投型「__NSCFString」（0x10a77f4a0）爲「NSDictionary中」（0x10a780288）的價值。在「更新」行。這是我第一次嘗試：

channelRef?.observe(.childChanged, with: { (snapshot) -> Void in 
     let value = snapshot.value as? NSDictionary 
     let readyToGoValue = value?["readyToGo"] as? Bool ?? false 
     let userID = value?["userID"] as? String ?? "" 
     var amountOfPlayers = value?["currentPlayers"] as? Int ?? 0 
     let changedCreator = value?["creator"] as? String ?? "" 
     print(snapshot) 
     let currentUser = FIRAuth.auth()?.currentUser?.uid 
     print(changedCreator) 
     print(amountOfPlayers) 
     if changedCreator != "" 
     { 
      print("changed creator") 
      self.creator = changedCreator 
     } 

這不起作用。

快照（創造者）喜

但是打印（「改變的創造者」）從未被執行：當改變在火力地堡的創造者（只是一個字符串），我添加打印時（快照）得到這個的圖片。爲什麼是這樣？

編輯：這是我如何得到channelRef ?:

super.prepare(for: segue, sender: sender) 
if let channel = sender as? Channel { 
    let chatVc = segue.destination as! channelMultiplayerViewController 
    chatVc.channel = channel 
    chatVc.channelRef = channelRef.child(channel.id) 
    chatVc.usersKey = userKey 

} 

打印的詳細數據：

 print("path channel ref: " + "\(self.channelRef)") 
     print("snapshot: " + "\(snapshot)") 
     print("value: " + "\(value)") 

-path通道編號：可選（https://X.com/channels/-KeGKaJavH6uPYaSa7k4）

-snapshot：快照（創作者）新造物主

-value：無

更新：

數據結構：

這將爲現在的工作，但是是不是有更好的辦法？：

 if snapshot.key == "creator" 
     { 
      changedCreator = snapshot.value as! String 
     } 

另一個問題完全一樣，但上面與第一個問題的解決方案，這個問題就不會得到解決。當我嘗試獲取第一個子節點，所以第一個用戶，並試圖獲得他們的用戶ID，沒有任何工作。我使用這個代碼：

let firstChild = UInt(1) 
        self.channelRef?.queryLimited(toFirst: firstChild).observeSingleEvent(of: .value, with: { (snapshot) in 
         let value = snapshot.value as? NSDictionary 
         print(snapshot) 
         print(value) 
         let newCreator = value?.value(forKey: "userID") as? String 

         if newCreator != nil{ 
          print("Got the userID") 
         } 
         if snapshot.key == "userID" 
         { 
          print("Got the userID") 
         } 
        }) 
Snap (-KeJWMiXaL-FGp0J7b3u) { 
    "-KeJWO0V9kxgGnrACAtP" =  { 
     PictureVersion = 2; 
     readyToGo = 0; 
     userID = SZlQ76RLCJQpFa0CDhrgFJoYzrs2; 
     username = pietje; 
    }; 
} 
Optional({ 
    "-KeJWO0V9kxgGnrACAtP" =  { 
     PictureVersion = 2; 
     readyToGo = 0; 
     userID = SZlQ76RLCJQpFa0CDhrgFJoYzrs2; 
     username = pietje; 
    }; 
}) 

而這打印出來，所以沒有用戶ID給出。爲什麼是這樣？用戶標識就在那裏！我閱讀文檔，但它應該工作...

Answer 1

嘗試用chatVc.channelRef = channelRef