在recyclerview的onbindviewholder中显示进度条

t2a7ltrp  于 2021-09-29  发布在  Java
关注(0)|答案(1)|浏览(476)

我想在加载recyclerview中的元素（大约要填充150个元素）时显示活动中的progressbar（在subitemadapter.kt中），但现在这个progressbar根本不显示。这是我的密码：
currencylistfragment.kt

  1. class CurrencyListFragment : Fragment(), MainContract.View {
  3.     companion object {
  4.         private val TAG = CurrencyListFragment::class.qualifiedName
  5.     }
  7.     private val restModel: RestModel = RestModel()
  8.     private val handler: Handler = Handler(Looper.getMainLooper())
  9.     private lateinit var mainPresenter: MainPresenter
  10.     private lateinit var itemAdapter: ItemAdapter
  11.     private lateinit var _layoutManager: LinearLayoutManager
  12.     private lateinit var onChangeFragment: OnChangeFragment
  13.     private lateinit var currentDate: String
  14.     private var isLoading: Boolean = false
  15.     private var apiResponseList: MutableList<ApiResponse> = arrayListOf()
  16.     private var listSize: Int = 0
  18.     override fun onAttach(context: Context) {
  19.         super.onAttach(context)
  20.         try {
  21.             if (activity is OnChangeFragment) onChangeFragment = activity as OnChangeFragment
  22.         } catch (error: ClassCastException) {
  23.             error.message?.let { Log.e(TAG, it) }
  24.         }
  25.     }
  27.     // @formatter:off
  28.     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
  29.         return inflater.inflate(R.layout.currency_list_fragment, container, false)
  30.     }
  31.     // @formatter:on
  33.     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
  34.         super.onViewCreated(view, savedInstanceState)
  35.         _layoutManager = LinearLayoutManager(activity)
  36.         mainPresenter = MainPresenter(this, restModel, SharedPreferencesModel(activity as Activity))
  37.         currentDate = mainPresenter.convertCurrentDate()
  38.         if (mainPresenter.checkIfSuchDateExistsinSp(currentDate)) {
  39.             Log.i(TAG, "Date $currentDate already exists in SharedPreferences")
  40.             mainPresenter.processDateWithoutMakingACall(currentDate)
  41.         } else {
  42.             mainPresenter.makeACall(currentDate)
  43.             Log.i(TAG, "Date $currentDate does not exist in SharedPreferences. Retrofit call made")
  44.         }
  45.         mainPresenter.saveNumberOfMinusDaysIntoSp(0)
  46.         addScrollerListener()
  47.     }
  49.     override fun showProgressBarOnLoadingCurrencies() {
  50.         progress_bar.visibility = View.VISIBLE
  51.     }
  53.     override fun hideProgressBarOnFinishedLoadingCurrencies() {
  54.         progress_bar.visibility = View.GONE
  55.     }
  57.     override fun setRecyclerViewStateToLoading() {
  58.         if (apiResponseList.size > 0) {
  59.             apiResponseList.add(ApiResponse("", "", listOf(Currency("", 0f)), true))
  60.             itemAdapter.notifyItemInserted(apiResponseList.size - 1)
  61.         }
  62.     }
  64.     override fun removeRecyclerViewStetOfLoading() {
  65.         if (apiResponseList.size > 1) {
  66.             apiResponseList.removeAt(apiResponseList.size - 1)
  67.             listSize = apiResponseList.size
  68.             itemAdapter.notifyItemRemoved(listSize)
  69.         }
  70.         isLoading = false
  71.     }
  73.     override fun getApiResponseList(): List<ApiResponse> {
  74.         return apiResponseList
  75.     }
  77.     override fun showLogAboutExistingDateInSp(date: String) {
  78.         Log.i(TAG, "Date $date already exists in SharedPreferences (new element)")
  79.     }
  81.     override fun showLogAboutNotExistingDateInSp(date: String) {
  82.         Log.i(TAG, "Date $date does not exist in SharedPreferences. Retrofit call made (new element)")
  83.     }
  85.     override fun assignResponseToRecyclerview(apiResponse: ApiResponse?) {
  86.         rv_item.apply {
  87.             layoutManager = _layoutManager
  88.             apiResponseList.add(apiResponse!!)
  89.             itemAdapter = activity?.let { ItemAdapter(apiResponseList, it) }!!
  90.             adapter = itemAdapter
  91.         }
  92.     }
  94.     private fun addScrollerListener() {
  95.         rv_item.addOnScrollListener(object : RecyclerView.OnScrollListener() {
  96.             override fun onScrollStateChanged(rvItem: RecyclerView, newState: Int) {
  97.                 super.onScrollStateChanged(rvItem, newState)
  98.                 mainPresenter.processRvitemOnScroll(isLoading, rvItem, newState)
  99.             }
  100.         })
  101.     }
  103.     private fun loadMore() {
  104.         setRecyclerViewStateToLoading()
  105.         var numberOfDays = mainPresenter.getNumberOfMinusDays()
  106.         numberOfDays++
  107.         mainPresenter.saveNumberOfMinusDaysIntoSp(numberOfDays)
  108.         val dateMinusXDays = mainPresenter.currentDateMinusXDaysToStr(numberOfDays)
  110.         val nextLimit = listSize + 1
  111.         for (i in listSize until nextLimit) {
  113.             if (mainPresenter.checkIfSuchDateExistsinSp(dateMinusXDays)) {
  114.                 Log.i(TAG, "Date $dateMinusXDays already exists in SharedPreferences (new element)")
  115.                 handler.postDelayed({
  116.                     mainPresenter.processDateWithoutMakingACall(dateMinusXDays)
  117.                 }, 2000)
  118.             } else {
  119.                 Log.i(TAG, "Date $dateMinusXDays does not exist in SharedPreferences. Retrofit call made (new element)")
  120.                 mainPresenter.makeACall(dateMinusXDays)
  121.             }
  122.         }
  123.         itemAdapter.notifyDataSetChanged()
  124.     }
  126.     override fun notifyChangedItemAdapter() {
  127.         itemAdapter.notifyDataSetChanged()
  128.     }
  130.     override fun onDestroy() {
  131.         super.onDestroy()
  132.         restModel.cancelJob()
  133.     }
  134. }

itemadapter.kt

  1. class ItemAdapter(private var items: MutableList<ApiResponse>, private val activity: Activity) : RecyclerView.Adapter<RecyclerView.ViewHolder>() {
  3.     companion object {
  4.         private const val VIEW_TYPE_DATA = 0
  5.         private const val VIEW_TYPE_PROGRESS = 1
  6.     }
  8.     override fun onCreateViewHolder(parent: ViewGroup, p1: Int): RecyclerView.ViewHolder {
  9.         return when (p1) {
  10.             VIEW_TYPE_DATA -> {
  11.                 val view = LayoutInflater.from(parent.context).inflate(R.layout.item, parent, false)
  12.                 DataViewHolder(view, activity)
  13.             }
  14.             VIEW_TYPE_PROGRESS -> {
  15.                 val view = LayoutInflater.from(parent.context).inflate(R.layout.progress_bar_layout, parent, false)
  16.                 ProgressViewHolder(view)
  17.             }
  18.             else -> throw IllegalArgumentException("Different View type")
  19.         }
  20.     }
  22.     override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
  23.         if (holder is DataViewHolder)
  24.             holder.bind(items[position])
  25.     }
  27.     override fun getItemCount() = items.size
  29.     override fun getItemViewType(position: Int): Int {
  30.         val viewtype = items[position]
  31.         return when (viewtype.isLoading) {//if data is load, returns PROGRESSBAR viewtype.
  32.             true -> VIEW_TYPE_PROGRESS
  33.             false -> VIEW_TYPE_DATA
  34.         }
  35.     }
  37.     class DataViewHolder(view: View, activity: Activity) : RecyclerView.ViewHolder(view) {
  38.         private var isRvSubitemVisible = false
  39.         private val tvDate = view.tv_date
  40.         private val rvSubitem = view.rv_subitem
  41.         private val activity = activity
  43.         fun bind(apiResponse: ApiResponse) {
  44.             tvDate.text = String.format(itemView.context.getString(R.string.day_x), apiResponse.date)
  45.             tvDate.setOnClickListener {
  46.                 if (isRvSubitemVisible) {
  47.                     rvSubitem.visibility = View.GONE
  48.                     isRvSubitemVisible = false
  49.                 } else {
  50.                     rvSubitem.visibility = View.VISIBLE
  51.                     isRvSubitemVisible = true
  52.                 }
  53.             }
  54.             rvSubitem.apply {
  55.                 layoutManager = LinearLayoutManager(itemView.context)
  56.                 adapter = SubitemAdapter(apiResponse.rates, apiResponse.date, activity)
  57.             }
  58.         }
  59.     }
  61.     inner class ProgressViewHolder(view: View) : RecyclerView.ViewHolder(view)
  62. }

子项适配器.kt

  1. class SubitemAdapter(private val subitems: List<Currency>, private val day: String, private val activity: Activity) : RecyclerView.Adapter<SubitemAdapter.SubitemViewHolder>() {
  3.     override fun onCreateViewHolder(parent: ViewGroup, p1: Int): SubitemViewHolder {
  4.         val view = LayoutInflater.from(parent.context).inflate(R.layout.subitem, parent, false)
  5.         return SubitemViewHolder(view, day, activity)
  6.     }
  8.     override fun onBindViewHolder(holder: SubitemViewHolder, position: Int) {
  9.         if(position < subitems.size - 1) {
  10.             activity.progress_bar.visibility = View.VISIBLE
  11.         }
  12.         else
  13.             activity.progress_bar.visibility = View.GONE
  14.         holder.bind(subitems[position], position)
  15.     }
  17.     override fun getItemCount() = subitems.size
  19.     class SubitemViewHolder(view: View, day: String, activity: Activity) : RecyclerView.ViewHolder(view) {
  20.         private val subitemRootView = view.subitem_root
  21.         private val tvCurrencyName = view.tv_currency_name
  22.         private val tvCurrencyValue = view.tv_currency_value
  23.         private val day = day
  24.         private val activity = activity
  25.         fun bind(currency: Currency, position: Int) {
  26.             subitemRootView.setOnClickListener { v ->
  27.                 activity as OnChangeFragment
  28.                 activity.changeFragment(SpecificCurrencyFragment(), ChangeFragmentData(hashMapOf(currency.currencyName to currency.currencyValue.toString()), day))
  29.             }
  30.             tvCurrencyName.text = currency.currencyName
  31.             tvCurrencyValue.text = currency.currencyValue.toString()
  32.         }
  33.     }
  34. }

这是我认为一切可以帮助我的。但是如果你需要更多的东西，那就用aks。任何帮助我们都将不胜感激。提前谢谢你！

kotlinandroidandroid-recyclerview

1条答案

按热度按时间
dfddblmv

dfddblmv1#

你已经通过了考试 List<Currency> 哪些是要加载到recyclerview中的项目。你不应该在里面检查这个 onBindViewHolder 因为当您将这些项目作为 argument 到 recyclerview adapter 相反，当您通过 List<Currency> 对于适配器，此时必须从活动本身更新progressbar。您可以编辑您的问题并为您的问题添加代码 Activity 如果这对你没有帮助，我会尽力回答你：）

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