RecyclerView - notifyDataSetChanged() - Kotlin - 不工作 [英] RecyclerView - notifyDataSetChanged() - Kotlin - Not Working
问题描述
在使用单独的 URL 调用更新数据后，我在 RecyclerView 中重新加载数据时遇到问题.FristFragment 调用 LoadDataFromUrl 并在 Recycler View 中显示数据.每个 Recycler 的视图项都有一个带有 OnSetClickListener 的按钮，该按钮调用另一个 URL 来更新项的名称数据.在用户更新项目名称并收到成功响应后，原始 myResponse 数据将更新为新项目的名称.当数据更新时，我需要在 Recycer View` 中重新加载数据，但我无法弄清楚.我花了两天时间试图修复它，但我无法让它运行.任何帮助将不胜感激！
I am having an issue with reloading data in RecyclerView after the data is updated with a separate URL call. The FristFragment calls LoadDataFromUrl and displays the data in the Recycler View. Each Recycler's view item has a button with OnSetClickListener that calls another URL to update item's name data. After the user updates the item's name and a successful response is received, then the original myResponse data is updated with the new item's name. When the data is updated, I need to reload data in the Recycer View` but I can not figure it out. I spent two days trying to fix it but I can't get it running. Any help would be greatly appreciated!
数据模型:
DataModel.kt
class MyResponse (var Status: String = "", val items: List<Items> = emptyList())
class Items(var ItemId: String = "", var ItemName: String = "")
回收者视图代码:
Adapter.kt
var recyclerView: RecyclerView? = null
class MainAdapter(val myResponse: MyResponse): RecyclerView.Adapter<CustomViewHolder>(){
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): CustomViewHolder {
val layoutInflater = LayoutInflater.from(parent?.context)
val cellForRow = layoutInflater.inflate(R.layout.my_custom_cell, parent,false)
return CustomViewHolder(cellForRow)
}
override fun onBindViewHolder(holder: CustomViewHolder, position: Int) {
val item = myResponse.items.get(position)
//there is a button for each item in the list that will call a function ButtonPressed from Frist Fragment
holder.view.button.setOnClickListener {
val firstFragment = FirstFragment()
firstFragment.ButtonPressed(item.ItemId,item.ItemName, position)
}
holder.view.textView_ItemID = item.itemId
holder.view.textView_Item_Name = item.itemName
}
class CustomViewHolder(val view: View, var Items: Item? = null): RecyclerView.ViewHolder(view){
}
}
然后我有一个片段 Fragment.kt
Then I have a fragment Fragment.kt
FirstFragment.kt
class FirstFragment : Fragment() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
}
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
val rootView = inflater.inflate(R.layout.first_fragment, container, false)
return rootView
}
override fun onActivityCreated(savedInstanceState: Bundle?) {
super.onActivityCreated(savedInstanceState)
LoadDataFromUrl()
recyclerView.layoutManager = LinearLayoutManager(this.context,
LinearLayoutManager.HORIZONTAL, false)
}
//this function loads data on create view
fun LoadDataFromUrl(){
val url = "some_url"
val payload = "some_data_to_send"
val requestBody = payload.toRequestBody()
val request = Request.Builder()
.method("POST",requestBody)
.url(url)
.build()
val client = OkHttpClient()
client.newCall(request).enqueue(object : Callback {
override fun onFailure(call: Call, e: IOException) {
println("error")
}
override fun onResponse(call: Call, response: Response) {
val body = response?.body?.string()
val gson = GsonBuilder().create()
myResponse = gson.fromJson(body, MyResponse::class.java)
activity?.runOnUiThread {
if (myResponse.Status== "200"){
recyclerView.adapter = MainAdapter(myResponse)
}
}
}
})
}
fun ButtonPressed(itemId: String, itemName: String, position: Int){
val url = "some_another_url"
val payload = "some_another_data_to_send"
val requestBody = payload.toRequestBody()
val request = Request.Builder()
.method("POST",requestBody)
.url(url)
.build()
val client = OkHttpClient()
client.newCall(request).enqueue(object : Callback {
override fun onFailure(call: Call, e: IOException) {
println("error")
}
override fun onResponse(call: Call, response: Response) {
val body = response?.body?.string()
val gson = GsonBuilder().create()
val buttomPressedResponse = gson.fromJson(body, ButtonPressedResponse::class.java)
if (buttonPressedResponse.Status== "200") {
myResponse.response[position].Status = buttomPressedResponse.Status //will update existing object myResponse with a new item's name
//this is where I have a problem
recyclerView.adapter.notifyDataSetChanged()
}
}
}
}
我尝试了以下更改，但仍然出现错误.
I tried the following changes but I still get an error.
//I get this error: Fatal Exception: OkHttp Dispatcher Process. recyclerView must not be null. Then the app crashes and the view reloads. If I clcik the Button again I get an error saying: RecyclerView: No adapter atatched. Skipping layout.
activity?.runOnUiThread {
myResponse.response[position].Status = checkInOutResponse.Status //will update existing object myResponse with updated data
recyclerView.adapter?.notifyDataSetChanged()
}
我也尝试在它上面运行 runOnUiTHread 但这段代码没有任何反应
I also tried to run on it runOnUiTHread but nothing happens with this code
activity?.runOnUiThread {
myResponse.response[position].Status = checkInOutResponse.Status //will update existing object myResponse with updated data
recyclerView.adapter?.notifyDataSetChanged()
}
推荐答案
在 Adapter 中创建 var myResponse: MyResponse 变量
Create var myResponse: MyResponse variable in Adapter
Adapter.kt
var recyclerView: RecyclerView? = null
class MainAdapter(val myResponseInit: MyResponse): RecyclerView.Adapter<CustomViewHolder>(){
var myResponse: MyResponse
myResponse = myResponseInit
fun submitMyResponse(data: MyResponse) {
myResponse = data
}
//Rest of the code onCreateViewHolder etc.
}
每次收到响应时，在适配器上调用 submitMyResponse() 函数和 notifyDataSetChanged().
Call submitMyResponse() function and notifyDataSetChanged() on adapter everytime you receive response.
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