从儿童Firebase访问值 [英] Accessing values from Children Firebase

问题描述

我确实不太了解Swift 3.0 Firebase语法的更新，但是从快照子级检索值中的大多数似乎都是不可能的.为此，我使用如下代码段:

I am really not quite understanding the updates to the Swift 3.0 Firebase syntax, but most of all retrieving values from children of a snapshot seems to be impossible. To do so, I use a snippet like this:

 if let snapVal = snapshot.value as? [String: AnyObject] {
     for c in snapshot.children {
                        let cx = (c as! AnyObject)
                        let name = cx["NAME"] as! String

     }
}

我已经采取了许多方法，但是FIRDatabaseSnapshot在新的Swift 3更新中有很多限制，并且AnyObject不允许从对象读取值，并且类似NSDictionary的类型也没有孩子.非常感谢所有帮助，谢谢！

I have taken many approaches to this but FIRDatabaseSnapshot has many restrictions in the new Swift 3 update, and AnyObject does not allow for values to be read from the object and NSDictionary-like types do not have children either. All help is very appreciated, thank you!

推荐答案

您收到的类型为FIRDataSnapshot的snapShot实际上是符合 NSObject 的自定义类，因此只有符合以下条件的变量到FIRDataSnapshot可以访问FIRDataSnapshot提供的自定义功能，例如 .children .

The snapShot that you receive of type FIRDataSnapshot is actually a custom class conforming to NSObject, so only the variables conforming to FIRDataSnapshot can access the custom function that FIRDataSnapshot provides such as .children.

但是，当您访问一个值为snap.value解析为 [String:AnyObject] 的新变量时，基本上它成为NSDictionary，而NSDictionary没有任何参数.children.

But when you are accessing a new variable whose value is snap.value parsed as [String:AnyObject], basically it becomes a NSDictionary, and NSDictionary doesn't has any parameter .children.

  FIRDatabase.database().reference().child("your_Ref").observeSingleEvent(of: .value, with: {(snap) in

        for each in snap.children{

            print(each)


        }
      if let snapDict = snap.value as? [String:AnyObject]{

            for each in snapDict{

                let keyID = each.key
                let childValue = each.value["NAME"] as! String
            }
        }

    })

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