无法从Firebase实时数据库检索其中一个嵌套数据

Question

我在firebase中具有以下结构。

为了检索数据，我使用以下代码-

 mFirebaseDatabaseReference = FirebaseDatabase.getInstance().reference.child("androidchat").child("users").child("uid-6")

mFirebaseDatabaseReference?.addValueEventListener(object : ValueEventListener {
    override fun onCancelled(p0: DatabaseError?) {
        callback?.handleData(false, requestType)
    }

    override fun onDataChange(p0: DataSnapshot?) {
        var userModel: UserModel? = p0?.getValue<UserModel>(UserModel::class.java)

        }
    }
})

调用onDataChange（）时，p0包含除组数据之外的所有其他数据。

这是我的dataclass用户模型-

data class UserModel(var uid: String? = null,
                 var name: String? = null,
                 var image_url: String? = null,
                 var user_location: String? = null,
                 var email: String? = null,
                 var group: MutableMap<String, Boolean> = mutableMapOf(),
                 var deviceIds : MutableMap<String,String> = mutableMapOf(),
                 var online: Boolean? = null,
                 var unread_group_count: Int? = null,
                 var last_seen_online: String? = null,
                 var last_seen_message_timestamp: String? = null,
                 var admin: Boolean? = null,
                 var delete_till: String? = null,
                 var active: Boolean? = null)

这是我收到的数据快照-

DataSnapshot { key = uid-6, value = {deviceIds={cc2583f5a2c92eff=dafO8mlj7aa:APA91bETLdet4b-oUnyYAe-GU68BuI4Sw1iT0jGCkUZdjes-ybA_9ZgHtZO-AoApVXQL9NfatyCgSfPSO74fsCUMY-6AY_8826D5AROVkFlQSUs8VKO5_FswoQceTxZ }, last_seen_message_timestamp=1510664398869, name=Akash Nidhi, uid=uid-6, online=true, user_location=USA-OTHERS, image_url=https://s3.ap-south-1.amazonaws.com/employees/images/150528664259b8d9f29c385.jpeg} }

datasnapshot！中没有组！。

更新添加了此行mFirebaseDatabaseReference？。保持同步（错误）。它昨天工作了几次，现在不工作了！

Answer 1

我也面临同样的问题。但最后，我找到了解决办法。我的数据格式如下：

{
"name":"Deepak",
"date":"03 April 2018",
"match_number":"3",
"team_name1":"Delhi",
"team_name2":"Punjab"
}

我已经从match_number、team_name1和team_name2中删除了下划线（u），并使用了matchNumber、teamName1和teamName2。如下

 {
    "name":"Deepak",
    "date":"03 April 2018",
    "matchNumber":"3",
    "teamName1":"Delhi",
    "teamName2":"Punjab"
    }

它非常适合我。试试这个，也许对你也有用。