[英]I am trying to show recyclerView in Fragment but I am getting error
class FeedRecyclerAdapter (private val postList : ArrayList<Post>) : RecyclerView.Adapter<FeedRecyclerAdapter.PostHolder>() {
class PostHolder(val binding: FragmentDataBinding) : RecyclerView.ViewHolder(binding.root)
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): PostHolder {
val binding = FragmentDataBinding.inflate(LayoutInflater.from(parent.context),parent,false)
return PostHolder(binding)
}
override fun onBindViewHolder(holder: PostHolder, position: Int) {
holder.binding.verimText.text = postList.get(position).lsi
}
override fun getItemCount(): Int {
return postList.size
}
以下是为 recyclerView 编写的代码。
private lateinit var postArrayList : ArrayList<Post>
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
auth = Firebase.auth
firestore = Firebase.firestore
postArrayList = ArrayList<Post>()
getData()
}
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View {
_binding = FragmentDataBinding.inflate(inflater, container, false)
val view = binding.root
val recyclerView = view.findViewById(R.id.recyclerView) as RecyclerView
recyclerView.layoutManager = LinearLayoutManager(activity)
recyclerView.adapter = FeedRecyclerAdapter(postArrayList)
return view
}
private fun getData(){
firestore.collection("Posts").addSnapshotListener { value, error ->
if (error!=null){
Toast.makeText(requireContext(),error.localizedMessage,Toast.LENGTH_SHORT).show()
}else{
if (value !=null){
if (!value.isEmpty){
val documents = value.documents
for (document in documents){
val araziBoyutu = document.get("Arazi Boyutu") as String
val araziEgimi = document.get("Arazi Eğimi") as String
val panelBoyutu = document.get("Panel Boyutu") as String
val panelSayisi = document.get("Panel Sayisi") as String
val sehir = document.get("Şehir") as String
val post = Post(panelSayisi,panelBoyutu,araziEgimi,araziBoyutu,sehir)
postArrayList.add(post)
}
}
}
}
}
}
这里的代码是我定义 RecyclerView 并保存信息的部分。
我可以拉数据,我可以在firebase上看到,当我用println打印时,我可以在控制台中读取它,我可以go到应该写入文本的页面,但是我看不到这个数据我正在尝试打印的 verimText TextView。
添加帖子后尝试调用notifyDataSetChanged()
或notifyItemRangeInserted()
。
Recyclerview 应该在onViewCreated
方法中声明
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
val recyclerView = view.findViewById(R.id.recyclerView) as RecyclerView
recyclerView.layoutManager = LinearLayoutManager(activity)
recyclerView.adapter = FeedRecyclerAdapter(postArrayList)
}
移动这条线
recyclerView.adapter = FeedRecyclerAdapter(postArrayList)
至
val post = Post(panelSayisi,panelBoyutu,araziEgimi,araziBoyutu,sehir)
postArrayList.add(post)
recyclerView.adapter = FeedRecyclerAdapter(postArrayList)//move to here
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