我已经实现了RecyclerView.addOnScrolledToEnd以使用异步任务从服务器获取下一组数据。刚使用RecyclerView.addOnScrolledToEnd时工作正常。但在这里，我的问题是，一旦我达到了结束，我做了SwipeRefreshLayout.setOnRefreshListener（这里将数据重置为新记录）RecyclerView.addOnScrolledToEnd没有调用，并且分页在这种情况下不起作用。
分段
class RecentNewsFragment : Fragment(), LoaderManager.LoaderCallbacks<Cursor>, NewsAdapter.OnNewsCallBack, OnRefreshCallback {
private var rlProgressContainer: View? = null
private var listContainer: View? = null
private var pbViewMore: ProgressBar? = null
private var swipeRefreshLayout: SwipeRefreshLayout? = null
private var srlNoMessageRefreshLayout: SwipeRefreshLayout? = null
private var newsAdapter: NewsAdapter? = null
private var pageLimit: Int = 10
private var pageOffset: Int = 0
private var totalNewsCount: Int = 0
private var isAsyncDone: Boolean = false
private val mRecentNewsBroadCast = object : BroadcastReceiver() {
override fun onReceive(context: Context, intent: Intent) {
// Get extra data included in the Intent
restartLoader()
}
}
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?): View? {
// Inflate the layout for this fragment
val view = inflater.inflate(R.layout.fragment_recent_news, container, false)
initView(view)
return view
}
override fun onResume() {
super.onResume()
if(!Helper.isConnected(context!!)) {
Toast.makeText(context!!, context?.getString(R.string.no_connection), Toast.LENGTH_SHORT).show()
}
}
private fun initView(view: View) {
rlProgressContainer = view.findViewById(R.id.rl_progressContainer)
listContainer = view.findViewById(R.id.ll_list_container)
pbViewMore = view.findViewById(R.id.pb_view_more)
newsAdapter = NewsAdapter(context!!, null, this)
val recyclerView = view.findViewById<RecyclerView>(R.id.recycler_view)
recyclerView.layoutManager = LinearLayoutManager(context)
recyclerView.adapter = newsAdapter
recyclerView.addItemDecoration(DividerItemDecoration(context!!, DividerItemDecoration.VERTICAL))
recyclerView.setHasFixedSize(true)
recyclerView.itemAnimator = DefaultItemAnimator()
pbViewMore!!.visibility = View.GONE
srlNoMessageRefreshLayout = view.findViewById(R.id.srl_activities_no_message)
srlNoMessageRefreshLayout!!.visibility = View.GONE
swipeRefreshLayout = view.findViewById(R.id.swipe_refresh_feeds_page)
val pullToRefresh = PullToRefresh()
swipeRefreshLayout!!.setColorSchemeResources(android.R.color.holo_green_dark, android.R.color.holo_red_dark, android.R.color.holo_orange_dark, android.R.color.holo_purple)
swipeRefreshLayout!!.setOnRefreshListener(pullToRefresh)
srlNoMessageRefreshLayout!!.setColorSchemeResources(android.R.color.holo_green_dark, android.R.color.holo_red_dark, android.R.color.holo_orange_dark, android.R.color.holo_purple)
srlNoMessageRefreshLayout!!.setOnRefreshListener(pullToRefresh)
listContainer!!.visibility = View.GONE
rlProgressContainer!!.visibility = View.VISIBLE
loaderManager.initLoader(Constants.URL_RECENT_NEWS_LOADER, arguments, this)
startAsync(pageLimit, pageOffset)
fun RecyclerView.addOnScrolledToEnd(onScrolledToEnd: () -> Unit){
this.addOnScrollListener(object: RecyclerView.OnScrollListener(){
private val visibleThreshold = 5
private var loading = true
private var previousTotal = 0
override fun onScrollStateChanged(recyclerView: RecyclerView,
newState: Int) {
with(layoutManager as LinearLayoutManager){
val visibleItemCount = childCount
val totalItemCount = itemCount
val firstVisibleItem = findFirstVisibleItemPosition()
if (loading && totalItemCount > previousTotal){
loading = false
previousTotal = totalItemCount
}
if(!loading && (totalItemCount - visibleItemCount) <= (firstVisibleItem + visibleThreshold)){
onScrolledToEnd()
loading = true
}
}
}
})
}
recyclerView.addOnScrolledToEnd {
//What you want to do once the end is reached
pbViewMore!!.visibility = View.VISIBLE
startAsync(pageLimit, pageOffset)
}
}
private inner class PullToRefresh : SwipeRefreshLayout.OnRefreshListener {
override fun onRefresh() {
pbViewMore!!.visibility = View.GONE
pageOffset = 0
startAsync(pageLimit, pageOffset)
srlNoMessageRefreshLayout!!.isRefreshing = false
swipeRefreshLayout!!.isRefreshing = false
}
}
private fun startAsync(pageLimit: Int, pageOffset: Int) {
if(Helper.isConnected(context!!)) {
val recentAsync = RecentNewsAsync(context = this, pageLimit = pageLimit, pageOffset = pageOffset)
recentAsync.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR)
} else {
isAsyncDone = true
}
}
fun restartLoader() {
if(isAdded)
loaderManager.restartLoader(Constants.URL_RECENT_NEWS_LOADER, null, this)
}
override fun onCreateLoader(id: Int, args: Bundle?): Loader<Cursor> {
return NewsVo.getCursorLoader(context!!, NewsVo.NewsType.RECENT, 0)
}
override fun onLoadFinished(loader: Loader<Cursor>, cursor: Cursor?) {
if (loader.id == Constants.URL_RECENT_NEWS_LOADER) {
if(isAsyncDone) {
listContainer!!.visibility = View.VISIBLE
rlProgressContainer!!.visibility = View.GONE
}
if (cursor != null) {
newsAdapter!!.swapCursor(cursor)
newsAdapter!!.notifyDataSetChanged()
if (isAsyncDone && cursor.count > 0) {
srlNoMessageRefreshLayout!!.visibility = View.GONE
swipeRefreshLayout!!.visibility = View.VISIBLE
} else if(isAsyncDone){
srlNoMessageRefreshLayout!!.visibility = View.VISIBLE
swipeRefreshLayout!!.visibility = View.GONE
}
}
}
}
override fun onLoaderReset(loader: Loader<Cursor>) {
newsAdapter!!.swapCursor(null)
}
private class RecentNewsAsync internal constructor(context: RecentNewsFragment, private val pageLimit: Int, private val pageOffset: Int) : AsyncTask<Void, Void, Response<ArrayList<NewsVo>>>() {
private val context: WeakReference<RecentNewsFragment> = WeakReference(context)
override fun doInBackground(vararg p0: Void?): Response<ArrayList<NewsVo>> {
var response = Response<ArrayList<NewsVo>>()
try {
val lphService = LPHServiceFactory.getCALFService(context.get()?.context!!)
response = lphService.recentNews(pageLimit, pageOffset)
} catch (e: LPHException) {
e.printStackTrace()
response.setThrowable(e)
} catch (e: JSONException) {
e.printStackTrace()
response.setThrowable(e)
} catch (e: IOException) {
e.printStackTrace()
response.setThrowable(e)
}
return response
}
override fun onPostExecute(response: Response<ArrayList<NewsVo>>) {
super.onPostExecute(response)
context.get()?.isAsyncDone = true
context.get()?.pbViewMore?.visibility = View.GONE
if (response.isSuccess()) {
context.get()?.totalNewsCount = response.getMetaData() as Int
if(context.get() != null)
context.get()!!.pageOffset += response.getResult()?.size!!
context.get()?.restartLoader()
}
}
}
override fun onFavoriteClick(newsId: Int, isFavorite: Boolean) {
if(Helper.isConnected(context!!)) {
val weakReferenceContext = WeakReference(this.context!!)
val markFavoriteAsync = Helper.MarkFavoriteAsync(weakReferenceContext, newsId, isFavorite, this, 0)
markFavoriteAsync.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR)
} else {
Helper.showConfirmationAlertTwoButton(context!!, context!!.getString(R.string.internet_warning), object : ConfirmationAlertCallback {
override fun onPositiveButtonClick() {
onFavoriteClick(newsId, isFavorite)
}
override fun onNegativeButtonClick() {
}
override fun onNeutralButtonClick() {
}
})
}
}
override fun setRead(newsId: Int, isRead: Boolean) {
if(Helper.isConnected(context!!)) {
val weakReferenceContext = WeakReference(context!!)
val markReadAsync = Helper.MarkReadAsync(weakReferenceContext, newsId, isRead, this, 0)
markReadAsync.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR)
} else {
Helper.showConfirmationAlertTwoButton(context!!, context!!.getString(R.string.internet_warning), object : ConfirmationAlertCallback {
override fun onPositiveButtonClick() {
setRead(newsId, isRead)
}
override fun onNegativeButtonClick() {
}
override fun onNeutralButtonClick() {
}
})
}
}
override fun onViewClick(newsId: Int) {
val newsDetailIntent = Intent(context, NewsDetailActivity::class.java)
newsDetailIntent.putExtra(Constants.BUNDLE_NEWS_ID, newsId)
startActivityForResult(newsDetailIntent, Constants.REQUEST_CODE_RECENT_NEWS)
}
override fun onActivityCreated(savedInstanceState: Bundle?) {
super.onActivityCreated(savedInstanceState)
activity!!.registerReceiver(mRecentNewsBroadCast, IntentFilter(Constants.BROADCAST_RECENT_NEWS))
}
override fun onDetach() {
super.onDetach()
activity!!.unregisterReceiver(mRecentNewsBroadCast)
}
override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
super.onActivityResult(requestCode, resultCode, data)
if (requestCode == Constants.REQUEST_CODE_RECENT_NEWS && resultCode == Activity.RESULT_OK) {
restartLoader()
val intent1 = Intent(Constants.BROADCAST_FAVORITE_NEWS)
context!!.sendBroadcast(intent1)
val intent2 = Intent(Constants.BROADCAST_CATEGORIES)
context!!.sendBroadcast(intent2)
}
}
override fun onRefresh() {
restartLoader()
val intent1 = Intent(Constants.BROADCAST_FAVORITE_NEWS)
context!!.sendBroadcast(intent1)
val intent2 = Intent(Constants.BROADCAST_CATEGORIES)
context!!.sendBroadcast(intent2)
}
companion object {
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* @return A new instance of fragment RecentNewsFragment.
*/
fun newInstance(): RecentNewsFragment {
return RecentNewsFragment()
}
}
}
布局文件：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<LinearLayout
android:id="@+id/ll_list_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<android.support.v4.widget.SwipeRefreshLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/srl_activities_no_message"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:visibility="gone">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<TextView
android:id="@+id/tv_no_data_found"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:enabled="false"
android:fontFamily="sans-serif-light"
android:gravity="center"
android:text="@string/no_data"
android:textAppearance="?android:attr/textAppearanceMedium"
android:textColor="@android:color/black" />
</LinearLayout>
</android.support.v4.widget.SwipeRefreshLayout>
<android.support.v4.widget.SwipeRefreshLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/swipe_refresh_feeds_page"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="false"
android:visibility="visible">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.RecyclerView
android:id="@+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<ProgressBar
android:id="@+id/pb_view_more"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerInParent="true"
android:layout_gravity="center_horizontal"
android:theme="@style/ProgressBarTheme"
android:visibility="gone" />
</RelativeLayout>
</android.support.v4.widget.SwipeRefreshLayout>
</LinearLayout>
<RelativeLayout
android:id="@+id/rl_progressContainer"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:visibility="gone">
<ProgressBar
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_centerInParent="true"
android:layout_centerVertical="true"
android:theme="@style/ProgressBarTheme" />
</RelativeLayout>
</LinearLayout>
这是Recyclerview无休止的滚动，我从here得到它
public abstract class EndlessRecyclerOnScrollListener extends RecyclerView.OnScrollListener {
/**
* The total number of items in the dataset after the last load
*/
private int mPreviousTotal = 0;
/**
* True if we are still waiting for the last set of data to load.
*/
private boolean mLoading = true;
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
int visibleItemCount = recyclerView.getChildCount();
int totalItemCount = recyclerView.getLayoutManager().getItemCount();
int firstVisibleItem = ((LinearLayoutManager) recyclerView.getLayoutManager()).findFirstVisibleItemPosition();
if (mLoading) {
if (totalItemCount > mPreviousTotal) {
mLoading = false;
mPreviousTotal = totalItemCount;
}
}
int visibleThreshold = 5;
if (!mLoading && (totalItemCount - visibleItemCount)
<= (firstVisibleItem + visibleThreshold)) {
// End has been reached
onLoadMore();
mLoading = true;
}
}
public abstract void onLoadMore();
}
我在Kotlin MVP模式中使用它
rcyView_matches.addOnScrollListener(object : EndlessRecyclerOnScrollListener() {
override fun onLoadMore() {
item_progress_bar.setVisibility(View.VISIBLE)
offset = offset + 10
homeModel.matchesParametre(CommonUtility.getGlobalString(activity as Activity, "userId"), "" + offset)
}
})
和Adapter Insilization，最初我是在填充空列表并在覆盖方法中添加列表之后。
override fun matchesList(list: ArrayList<ProfileSelectedData>) {
avlodder.hide()
iv_nodata.visibility = View.GONE
matcheslist.addAll(list)
adapter.notifyDataSetChanged()
item_progress_bar.setVisibility(View.GONE)
}