点击项目后,回收器适配器反复读取数据(ANDROID KOTLIN)
当我点击回收项目,它移动到新的片段,但当回来 回收物品的数量会翻倍。我如何解决这个问题 所以它只传递一次项目,项目不会加倍。使用addOSnapshoListner也没有效果 提前谢谢 连接适配器的代码点击项目后,回收器适配器反复读取数据(ANDROID KOTLIN),android,kotlin,android-recyclerview,Android,Kotlin,Android Recyclerview,当我点击回收项目,它移动到新的片段,但当回来 回收物品的数量会翻倍。我如何解决这个问题 所以它只传递一次项目,项目不会加倍。使用addOSnapshoListner也没有效果 提前谢谢 连接适配器的代码 private var db =FirebaseFirestore.getInstance() private lateinit var userrecycler : RecyclerView var list = ArrayList<daxhboard_gridlayout_data&g
private var db =FirebaseFirestore.getInstance()
private lateinit var userrecycler : RecyclerView
var list = ArrayList<daxhboard_gridlayout_data>()
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.dashboard_screen, container, false)
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
if (list.isEmpty()){
getUserdata()
userrecycler = dashboard_grid_recycleView.findViewById(R.id.dashboard_grid_recycleView)
dashboard_grid_recycleView.layoutManager = GridLayoutManager(this.requireContext(), 2)
dashboard_grid_recycleView.setHasFixedSize(true)}}`
private fun getUserdata(){
db.collection("services")
.get()
.addOnSuccessListener { documents ->
for (document in documents) {
val imgurl = document.data["imageResource"].toString()
val text = document.data["text1"].toString()
list.add(daxhboard_gridlayout_data(imgurl,text))
dashboard_grid_recycleView.adapter = dashboard_gridlayout_adapter(list)
}
}
.addOnFailureListener { exception ->
Log.e("serf", "Error getting documents: ", exception)
}
}`
private var db=FirebaseFirestore.getInstance()
私有lateinit var userrecycler:RecyclerView
var list=ArrayList()
覆盖创建视图(充气机:布局充气机,容器:ViewGroup?,savedInstanceState:Bundle?):视图?{
//为该碎片膨胀布局
返回充气机。充气(右侧布局仪表板屏幕,容器,假)
}
覆盖已创建的视图(视图:视图,保存状态:捆绑?){
super.onViewCreated(视图,savedInstanceState)
if(list.isEmpty()){
getUserdata()
userrecycler=dashboard\u grid\u recycleView.findViewById(R.id.dashboard\u grid\u recycleView)
dashboard\u grid\u recycleView.layoutManager=GridLayoutManager(this.requireContext(),2)
dashboard_grid_recycleView.setHasFixedSize(true)}`
private fun getUserdata(){
db.收款(“服务”)
.get()
.addOnSuccessListener{文档->
for(文档中的文档){
val imgurl=document.data[“imageResource”].toString()
val text=document.data[“text1”].toString()
添加(数据板\网格布局\数据(imgurl,文本))
dashboard\u grid\u recycleView.adapter=仪表板\u gridlayout\u适配器(列表)
}
}
.addOnFailureListener{异常->
Log.e(“serf”,“获取文档时出错:”,异常)
}
}`
适配器代码
class dashboard\u gridlayout\u适配器(私有val sampledata:ArrayList):
适配器(){
override fun onCreateViewHolder(父级:ViewGroup,viewType:Int):dashboard_viewholder{
val itemView=
LayoutFlater.from(parent.context)。充气(R.layout.dashboard\u gridlayout\u single\u item\u design,parent,
(错误)
返回仪表板视图保持架(项目视图)
}
覆盖BindViewHolder(支架:仪表板\视图支架,位置:Int){
val currentitem=采样数据[位置]
滑动.with(holder.itemView).load(currentitem.imageResource)
.into(holder.imageView)
holder.textView.text=currentitem.text1
holder.itemView.setOnClickListener{
val appCompatActivity=it.context作为appCompatActivity
appCompatActivity.supportFragmentManager.beginTransaction()
.replace(R.id.Activity\u frag\u container,service\u providers\u list())
.addToBackStack(空)
.commit()
}
}
重写getItemCount()=sampledata.size
类dashboard_viewholder(itemView:View):RecyclerView.viewholder(itemView){
val imageView:imageView=itemView.dashboard_适配器_图像
val textView:textView=itemView.dashboard_适配器_text
}
在向列表中添加项目之前,需要清除列表。
只需添加list.clear()行,就可以了
private fun getUserdata(){
db.collection("services")
.get()
.addOnSuccessListener { documents ->
list.clear()
for (document in documents) {
val imgurl = document.data["imageResource"].toString()
val text = document.data["text1"].toString()
list.add(daxhboard_gridlayout_data(imgurl,text))
dashboard_grid_recycleView.adapter = dashboard_gridlayout_adapter(list)
}
}
.addOnFailureListener { exception ->
Log.e("serf", "Error getting documents: ", exception)
}
}
我还建议您看看片段的生命周期。如果我删除list,它会起作用。连接适配器代码的empty()条件表单并使用list.clear()在OnSuccessListener中起作用。
list.clear()
开头的行在这里是至关重要的
private fun getUserdata(){
db.collection("services")
.get()
.addOnSuccessListener { documents ->
list.clear()
for (document in documents) {
val imgurl = document.data["imageResource"].toString()
val text = document.data["text1"].toString()
list.add(daxhboard_gridlayout_data(imgurl,text))
dashboard_grid_recycleView.adapter = dashboard_gridlayout_adapter(list)
}
}
.addOnFailureListener { exception ->
Log.e("serf", "Error getting documents: ", exception)
}
}