大家好，我已经创建了RecyclerView并使用AsyncTask获取数据。第一步，我要显示10个第一个数据并加载更多10个数据，直到到达最后一个数据。 之后，我想将进度条作为页脚来加载数据。
这是我的MutationRecyclerViewAdapter代码
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
val view = LayoutInflater.from(parent.context)
.inflate(R.layout.item_mutation, parent, false)
return ViewHolder(view)
}
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
holder.mItem = mValues[position]
holder.itemView.text_transaction_type.text = getTransactionTypeString(mValues[position].transactionType)
holder.itemView.text_transaction_number.text = mValues[position].transactionID
holder.itemView.text_transaction_date.text = AppUtil.getDefaultDateFormat(mValues[position].transactionDate)
holder.itemView.text_balance.text = mValues[position].balance
holder.itemView.text_amount.text = mValues[position].amount
holder.itemView.text_merchant_name.text = mValues[position].merchant
if(mValues[position].transactionType != null) {
when (mValues[position].transactionType) {
"PR", "ST" -> {
holder.itemView.image_transaction_icon.setImageResource(R.drawable.ic_action_purchase)
holder.itemView.image_transaction_icon.background = ContextCompat.getDrawable(mContext!!, R.drawable.bg_circle)
holder.itemView.text_transaction_type.setTextColor(ContextCompat.getColor(mContext!!, R.color.orange))
holder.itemView.text_product_name.text = holder.mItem!!.merchant
holder.itemView.text_amount.setTextColor(ContextCompat.getColor(mContext!!, R.color.orange))
//holder.itemView.text_product_name.visibility = View.VISIBLE
holder.itemView.image_balance.setImageResource(R.drawable.ic_min_orange)
}
"RD" -> {
holder.itemView.image_transaction_icon.setImageResource(R.drawable.ic_action_withdraw_rotated)
holder.itemView.image_transaction_icon.background = ContextCompat.getDrawable(mContext!!, R.drawable.bg_circle)
holder.itemView.text_transaction_type.setTextColor(ContextCompat.getColor(mContext!!, R.color.orange))
holder.itemView.image_balance.setImageResource(R.drawable.ic_plus)
holder.itemView.text_amount.setTextColor(ContextCompat.getColor(mContext!!, R.color.orange))
}
"CI" -> {
holder.itemView.text_transaction_type.setTextColor(ContextCompat.getColor(mContext!!, R.color.green_grass_dark))
holder.itemView.image_transaction_icon.background = ContextCompat.getDrawable(mContext, R.drawable.bg_circle_green)
holder.itemView.image_transaction_icon.setImageResource(R.drawable.ic_action_cash_in)
holder.itemView.image_balance.setImageResource(R.drawable.ic_plus_green)
holder.itemView.text_amount.setTextColor(ContextCompat.getColor(mContext, R.color.green_grass_dark))
}
"CO", "FCO", "XX" -> {
holder.itemView.image_transaction_icon.background = ContextCompat.getDrawable(mContext!!, R.drawable.bg_circle)
holder.itemView.image_transaction_icon.setImageResource(R.drawable.ic_action_withdraw_rotated)
holder.itemView.text_transaction_type.setTextColor(ContextCompat.getColor(mContext, R.color.orange))
holder.itemView.image_balance.setImageResource(R.drawable.ic_min_orange)
holder.itemView.text_amount.setTextColor(ContextCompat.getColor(mContext, R.color.orange))
}
"AD" -> {
holder.itemView.image_transaction_icon.setImageResource(R.drawable.ic_action_adjustment)
holder.itemView.image_transaction_icon.background = ContextCompat.getDrawable(mContext!!, R.drawable.bg_circle_gray)
holder.itemView.text_transaction_type.setTextColor(ContextCompat.getColor(mContext, R.color.gray_dark))
holder.itemView.image_balance.setImageResource(R.drawable.ic_plus)
holder.itemView.text_amount.setTextColor(ContextCompat.getColor(mContext, R.color.gray_dark))
}
"RBY"->{
holder.itemView.image_transaction_icon.setImageResource(R.drawable.ic_action_adjustment)
holder.itemView.image_transaction_icon.background = ContextCompat.getDrawable(mContext!!, R.drawable.bg_circle_gray)
holder.itemView.text_transaction_type.setTextColor(ContextCompat.getColor(mContext, R.color.gray_dark))
holder.itemView.image_balance.setImageResource(R.drawable.ic_plus)
holder.itemView.text_amount.setTextColor(ContextCompat.getColor(mContext, R.color.gray_dark))
}
"TO" -> {
holder.itemView.image_transaction_icon.background = ContextCompat.getDrawable(mContext!!, R.drawable.bg_circle_blue)
holder.itemView.image_transaction_icon.setImageResource(R.drawable.ic_action_transfer)
holder.itemView.text_transaction_type.setTextColor(ContextCompat.getColor(mContext!!, R.color.blue_foreground))
holder.itemView.image_balance.setImageResource(R.drawable.ic_minus_blue)
holder.itemView.text_amount.setTextColor(ContextCompat.getColor(mContext, R.color.blue_foreground))
}
"TI", "BY" -> {
holder.itemView.image_transaction_icon.background = ContextCompat.getDrawable(mContext!!, R.drawable.bg_circle_green)
holder.itemView.image_transaction_icon.setImageResource(R.drawable.ic_action_transfer_in)
holder.itemView.text_transaction_type.setTextColor(ContextCompat.getColor(mContext!!, R.color.green_grass_dark))
holder.itemView.image_balance.setImageResource(R.drawable.ic_plus_green)
holder.itemView.text_amount.setTextColor(ContextCompat.getColor(mContext, R.color.green_grass_dark))
}
else -> {
holder.itemView.image_transaction_icon.setImageResource(R.drawable.ic_action_adjustment)
holder.itemView.image_transaction_icon.background = ContextCompat.getDrawable(mContext!!, R.drawable.bg_circle_gray)
holder.itemView.text_transaction_type.setTextColor(ContextCompat.getColor(mContext, R.color.gray_dark))
holder.itemView.image_balance.visibility = View.INVISIBLE
holder.itemView.text_amount.setTextColor(ContextCompat.getColor(mContext, R.color.gray_dark))
}
}
} else {
holder.itemView.image_transaction_icon.setImageResource(R.drawable.ic_action_adjustment)
holder.itemView.image_transaction_icon.background = ContextCompat.getDrawable(mContext!!, R.drawable.bg_circle_gray)
holder.itemView.text_transaction_type.setTextColor(ContextCompat.getColor(mContext, R.color.gray_dark))
holder.itemView.image_balance.visibility = View.INVISIBLE
holder.itemView.text_amount.setTextColor(ContextCompat.getColor(mContext, R.color.gray_dark))
}
holder.mView.setOnClickListener {
mListener?.onMutationFragmentInteraction(holder.mItem!!)
}
holder.mView.setOnLongClickListener {
mListener?.onLongMutationFragmentInteraction(holder.mItem!!)
false
}
}
private fun getTransactionTypeString(type: String): String {
return when(type) {
"PR" -> mContext!!.getString(R.string.purchase)
"CI" -> mContext!!.getString(R.string.cash_in)
"CO" -> mContext!!.getString(R.string.cash_out)
"RD" -> mContext!!.getString(R.string.redeem)
"TI" -> mContext!!.getString(R.string.transfer_in)
"TO" -> mContext!!.getString(R.string.transfer_out)
"FCO" -> mContext!!.getString(R.string.cash_out)
"XX" -> mContext!!.getString(R.string.cash_out)
"BY" -> mContext!!.getString(R.string.purchase)
"ST" -> mContext!!.getString(R.string.settlement)
"AD" -> mContext!!.getString(R.string.adjustment)
"RBY" ->mContext!!.getString(R.string.rby)
else -> return type
}
}
override fun getItemCount(): Int {
return mValues.size
}
inner class ViewHolder(val mView: View) : RecyclerView.ViewHolder(mView) {
var mItem: MutationItem? = null
}
这是我的MutationFragment
private var maxItemSize = -1
private var mListener: OnMutationFragmentInteractionListener? = null
lateinit var adapter : MutationRecyclerViewAdapter
lateinit var refreshButton : ImageView
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
if (arguments != null) {
maxItemSize = arguments?.getInt(MAX_ITEMS_SIZE, -1)!!
}
}
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
val view = inflater.inflate(R.layout.fragment_mutation, container, false)
(activity as AppCompatActivity).supportActionBar?.title = "MutationFragment"
return view
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
MutationContent.ITEMS.clear()
GetTransactionTask(context!!, this).execute()
mutation_list.layoutManager = LinearLayoutManager(context)
adapter = MutationRecyclerViewAdapter(MutationContent.getSavedTransactions(context, maxItemSize), mListener, context)
refreshLayout.apply {
scrollUpChild = mutation_list
setOnRefreshListener {
isRefreshing = false
GetTransactionTask(context!!, this@MutationFragment).execute()
}
}
}
fun toggleView(isEmpty : Boolean){
if(isEmpty){
progress_bar?.visibility = View.GONE
mutation_list?.visibility = View.GONE
//refreshButton.visibility = View.GONE
text_no_mutation?.visibility = View.VISIBLE
}
else{
progress_bar?.visibility = View.GONE
mutation_list?.visibility = View.VISIBLE
//refreshButton?.visibility = View.GONE
text_no_mutation?.visibility = View.GONE
}
activity?.invalidateOptionsMenu()
}
override fun onGetTransactionSuccess(response: ResponseRequestMutasiSaldo) {
MutationContent.import(context, response, maxItemSize)
adapter = MutationRecyclerViewAdapter(MutationContent.getSavedTransactions(context, maxItemSize),
mListener, context)
mutation_list?.adapter = adapter
if(adapter.mValues.isEmpty()) {
text_no_mutation?.setText(getString(R.string.no_mutation))
} else {
text_no_mutation?.setText(getString(R.string.load_mutation))
}
toggleView(adapter.mValues.isEmpty())
}
override fun onAttach(context: Context?) {
super.onAttach(context)
if (context is OnMutationFragmentInteractionListener) {
mListener = context
} else {
throw RuntimeException(context!!.toString() + " must implement OnSettingFragmentInteractionListener")
}
}
override fun onDetach() {
super.onDetach()
mListener = null
}
override fun onTransactionFailed(response: ResponseRequestMutasiSaldo) {
adapter = MutationRecyclerViewAdapter(
MutationContent.getSavedTransactions(context, maxItemSize),
mListener, context)
mutation_list?.adapter = adapter
toggleView(adapter.mValues.isEmpty())
/*if(activity != null)
Toasty.error(activity!!,response.errorMessage).show()*/
}
interface OnMutationFragmentInteractionListener {
fun onMutationFragmentInteraction(item: MutationItem)
fun onLongMutationFragmentInteraction(item: MutationItem)
}
companion object {
val MAX_ITEMS_SIZE = "MAX_ITEM_SIZE"
}
这是我的Asynctask类
override fun doInBackground(vararg p0: Void?): ResponseRequestMutasiSaldo? {
return ResourceService(context).requestMutasiSaldo()
}
override fun onPostExecute(result: ResponseRequestMutasiSaldo?) {
if(result != null && (result.error.equals(AppUtil.RESPONSE_ERROR_CODE_EXPIRY) || result.success.equals(AppUtil.RESPONSE_SUCCESS_CODE_EXPIRY))){
EventBus.getDefault().post(SessionExpiry(result.message?:""))
return
}
if(result != null && result.success.equals("1")) {
listener.onGetTransactionSuccess(result)
}
if(result != null && result.error.equals("1")){
listener.onTransactionFailed(result)
return
}
}
我已经成功地从Web服务获取了所有数据，现在我已经尝试过使用documentation这样的EndlessRecyclerViewListener并使用多个引用来实现我的任务。但是功能AddOnScroll不能正常工作，我也不怎么理解它是如何工作的。如果要使用EndlessRecyclerViewListener，该怎么办？还是有其他方法可以在不使用EndlessRecyclerViewListener类的情况下实现这一目标？
答案 0 :(得分：0)
使用addOnScrollListener进行此操作。
val pageLimit: Int = 10//row returned each time on scroll
var noMoreItems: Boolean = false
像这样在您的回收视图中使用addOnScrollListener。
dataRecyclerView.addOnScrollListener(object : androidx.recyclerview.widget.RecyclerView.OnScrollListener() {
override fun onScrollStateChanged(recyclerView: androidx.recyclerview.widget.RecyclerView, newState: Int) {
super.onScrollStateChanged(recyclerView, newState)
if (!recyclerView.canScrollVertically(1)) {
if (!utility.isConnected(mContext)) {
Toast.makeText(mContext, "No internet", Toast.LENGTH_SHORT).show()
return
}
if (noMoreItems)
return
val lastPage: String
val nextPage: Int
if (dataArrayList.size > 0) {
lastPage = ((dataArrayList.size - 1) / pageLimit).toInt().toString()
nextPage = Integer.parseInt(lastPage) + 1
} else {
nextPage = 1;
}
loadRecords(nextPage.toString())
}
}
})
在loadRecords()中，您应该使用页码呼叫asynctask。
返回的行数少于noMOreItems=true时，请设置pageLimit。