不能调用非函数类型的值'Any？!' : - Firebase,Swift3

Question

在转到Swift 3 之前,这是我的代码:

ref.observeEventType(.ChildAdded, withBlock: { snapshot in
            let currentData = snapshot.value!.objectForKey("Dogs")
            if currentData != nil {
            let mylat = (currentData!["latitude"])! as! [String]
            let mylat2 = Double((mylat[0]))
            let mylon = (currentData!["longitude"])! as! [String]
            let mylon2 = Double((mylon[0]))
            let userid = (currentData!["User"])! as! [String]
            let userid2 = userid[0]
            let otherloc = CLLocation(latitude: mylat2!, longitude: mylon2!)
            self.distanceBetweenTwoLocations(self.currentLocation, destination: otherloc, userid: userid2)
            }
        })

这是我移动到Swift 3 后的代码:

ref.observe(.childAdded, with: { snapshot in
            let currentData = (snapshot.value! as AnyObject).object("Dogs")
            if currentData != nil {
                let mylat = (currentData!["latitude"])! as! [String]
                let mylat2 = Double((mylat[0]))
                let mylon = (currentData!["longitude"])! as! [String]
                let mylon2 = Double((mylon[0]))
                let userid = (currentData!["User"])! as! [String]
                let userid2 = userid[0]
                let otherloc = CLLocation(latitude: mylat2!, longitude: mylon2!)
                self.distanceBetweenTwoLocations(self.currentLocation, destination: otherloc, userid: userid2)
            }
        })

然后我在第二行收到错误:

不能调用非函数类型的值'Any？!'

我唯一尝试的是将第二行更改为此代码:

snapshot.value as! [String:AnyObject]

但它不对,没有包含"狗",它给了我一个警告,distanceBetweenTwoLocations代码从未使用过.

Answer 1

看到的问题是,当您实例化并初始化变量时,您告诉它它将接收的值将是该类型为的快照中value名为Dogspresent 的对象AnyObject.

但是snapshot.value类型为Dictionary ie [String:AnyObject],NSDictionary..

Dogs您检索的节点类型为Dictionary或Array.

基本上,您应该避免将值存储在AnyObject类型的变量中

试试这个:-

      FIRDatabase.database().reference().child("Posts").child("post1").observe(.childAdded, with: { snapshot in
        if let currentData = (snapshot.value! as! NSDictionary).object(forKey: "Dogs") as? [String:AnyObject]{

            let mylat = (currentData["latitude"])! as! [String]
            let mylat2 = Double((mylat[0]))
            let mylon = (currentData["longitude"])! as! [String]
            let mylon2 = Double((mylon[0]))
            let userid = (currentData["User"])! as! [String]
            let userid2 = userid[0]
            let otherloc = CLLocation(latitude: mylat2!, longitude: mylon2!)
            self.distanceBetweenTwoLocations(self.currentLocation, destination: otherloc, userid: userid2)
        }
    })

PS: -看到你的JSON结构你可能想把它转换成字典而不是数组