json - firebase 数组解析 json 总是失败

Question

这是我打印的 print(childSnap) 并尝试使用 as? [String : Any] 但任何替代方案总是失败。

   Snap (-Ki9GkBvIMofJiIByVeI) {
        location = Cupertino;
        name = "find hotel ";
        userCreatedId = "";
    }

---

 let ref = FIRDatabase.database().reference()
        let allGroup = ref.child("all-group")
        allGroup.observe(.childAdded, with: { (snapshot) in
            for  childSnap in snapshot.children{       
                   print(childSnap)

                if let _childSnap = childSnap as? [String : Any] {
                    //this code not execute.. 
                    let group = Group(json: _childSnap )
                    groups.append(group)
                }
            }

        }, withCancel: nil)
    }

Answer 1

将 childSnap 类型转换为 FIRDataSnapshot，然后访问它的 value 属性。

if let _childSnap = (childSnap as! FIRDataSnapshot).value as? [String : Any] {
    let group = Group(json: _childSnap )
    groups.append(group)
}