Swift Firebase訪問子快照數據

Question

我目前正試圖從Swift中的子快照訪問數據。這裏是我的代碼，我有（其中斯威夫特3 /火力地堡更新之前曾）：

if let achievements = snapshot1.childSnapshotForPath("Achievements").children.allObjects as? [FIRDataSnapshot] { 


        if achievements.count != 0 { 

         if let val = achievements[0].value!["somevalue"] as? Int { 
          self.dict["somevalue"] = val 
         } 


        } 

因此，我想在這裏做的，是創建一個子快照（成就）的變量，並獲得子級快照數據。成就[0]將簡單地返回第一個值。但是，這似乎並不奏效。我應該如何處理這個問題？

我目前做這個快照裏面已經（的 'observeType：.ChildAdded'）

我的火力地堡DB是這樣的：

Achievements{ 

randomId1 { 
somevalue : somevalue 
} 

randomId2 { 
somevalue2 : somevalue2 
} 
} 

更新代碼：

func loadData() { 

     ref.child("Players").observe(FIRDataEventType.childAdded) { (snapshot:FIRDataSnapshot) in 

      if let value = snapshot.value as? [String:AnyObject], let username = value["Username"] as? String { 

      } 

      if let value = snapshot.value as? [String:AnyObject], let ranking = value["Rank"] as? String { 

      } 

      if let childSnapshot = snapshot.childSnapshot(forPath: "Achievements").children.allObjects as? [FIRDataSnapshot] { 

       if childSnapshot.count != 0 { 

        if let achievement1 = childSnapshot[0].value!["Rookie"] as? String { 
         print(achievement1) 
        } 

       } 
      } 

     } 

    } 

JSON樹：

Players { 

PlayerID { 

Username 

Rank 

Achievements { 

Rookie: yes 

} 


} 

Answer 1

請嘗試： -

if let childSnapshot = snapshot.childSnapshot(forPath: "Achievements") as? FIRDataSnapshot{ 

       if let achievementDictionary = childSnapshot.value as? [String:AnyObject] , achievementDictionary.count > 0{ 

        if let achieveMedal = achievementDictionary["Rookie"] as? String { 

         print(achieveMedal) 

      }   
     } 
    }