更新到Swift 3后，“Any”类型没有下标成员

Here is my code in Swift:

这是我在Swift中的代码：

currentUserFirebaseReference.observeSingleEvent(of: .value, with: { (snapshot: FIRDataSnapshot) in
        let UID = snapshot.key
        let pictureURL = snapshot.value!["pictureURL"] as! String
        let name = snapshot.value!["displayname"] as! String
        let currentUser = Person(name: name, bio: "", UID: UID, pictureURL: pictureURL)
        self.currentUserInfo = currentUser
            })
cu