• • 编辑**

我改变了我的代码并且得到了一个结果但是它把数据分解成分开的值.它从数据库中为每个孩子读取所有数据.我有2个孩子但是它只检索最后一个孩子的数据并且分开显示它的值.它从变量eta_text存储它的值

override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        clear_all = view.findViewById(R.id.clear_all)

        notificationView = view.findViewById(R.id.notificationList)

        notificationArray = arrayListOf()

        getNotifData()

        var linearLayoutManager = LinearLayoutManager(context)
        notificationView.layoutManager = linearLayoutManager
        notificationView.setHasFixedSize(true)
 
    }

     private fun getNotifData() {
         val user = FirebaseAuth.getInstance().currentUser
         val useremail = user!!.email

         dbref = FirebaseDatabase.getInstance().reference
         dbref.child("Students").orderByChild("email").equalTo(useremail.toString()).addValueEventListener(object : ValueEventListener{
             override fun onDataChange(snapshot: DataSnapshot) {
                 for (ds in snapshot.children) {
                     val idNumber: String? = ds.key

                     dbref.child("Notification").child(idNumber.toString()).addValueEventListener(object : ValueEventListener{
                         override fun onDataChange(dsnapshot: DataSnapshot) {
                             for (dsd in dsnapshot.children) {
                                 val key: String? = dsd.key
                                 dbref.child("Notification").child(idNumber.toString()).child(key.toString()).addValueEventListener(object : ValueEventListener{
                                     override fun onDataChange(dsnap: DataSnapshot) {
                                         notificationArray.clear()
                                         if (dsnap.exists()){

                                             for (queueSnapshot in dsnap.children){

                                                 notificationArray.add(Notification(queueSnapshot.value.toString()))
                                             }

                                             notifadapter = MyAdapter_Notification(notificationArray)
                                             notificationView.adapter = notifadapter
                                         }
                                         
                                     }

                                     override fun onCancelled(error: DatabaseError) {
                                         TODO("Not yet implemented")
                                     }
                                 })
                             }
                         }

                         override fun onCancelled(error: DatabaseError) {
                             TODO("Not yet implemented")
                         }
                     })
                 }

             }

             override fun onCancelled(error: DatabaseError) {
                 TODO("Not yet implemented")
             }

         })
     }

我的数据类

package com.example.sqms

data class Notification(var eta_text : String ?= null,
                        var office_name : String ?= null,
                        var time_text : String ?= null)

我的适配器

class MyAdapter_Notification (private val notificationList : ArrayList<Notification>)
    : RecyclerView.Adapter<MyAdapter_Notification.MyViewHolder>() {

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {

        val notificationView = LayoutInflater.from(parent.context).inflate(R.layout.notification_view,parent,false)

        return MyViewHolder(notificationView)
    }

    override fun onBindViewHolder(holder: MyViewHolder, position: Int) {

        val currentItem = notificationList[position]

        holder.eta_text.text = currentItem.eta_text
        holder.office_name.text = currentItem.office_name
        holder.time_text.text = currentItem.time_text

    }

    override fun getItemCount(): Int {
        return notificationList.size
    }

    inner class MyViewHolder(notificationView : View) : RecyclerView.ViewHolder(notificationView){

        val eta_text : TextView = itemView.findViewById(R.id.eta_text)
        val office_name : TextView = itemView.findViewById(R.id.office_name)
        val time_text : TextView = itemView.findViewById(R.id.time_text)

    }
}

下图是来自数据库database的值
下图是单独显示的数据notification recycler view