背景:
我正在通过添加 RecyclerView
函数来使用 addOnScrollListener
实现分页逻辑。
面临的问题:
当 RecyclerView 适配器加载 dy 值为 0 时调用 onScrolled
方法一次。但是,当列表在滚动时到达其末尾时,不会触发 onScrolled
方法,而 onScrollStateChanged
被正确触发。
这是我的适配器:
HistoryAdapter(Context context, ArrayList<HistoryItem> items, RecyclerView recyclerView) {
inflater = LayoutInflater.from(context);
this.items = items;
preferences = PreferenceManager.getDefaultSharedPreferences(context);
this.context = context;
this.recyclerView = recyclerView;
final LinearLayoutManager linearLayoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
@Override
public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
Timber.w("onScrolled.. %s", dy);
if (dy > 0) {
totalItemCount = linearLayoutManager.getItemCount();
lastVisibleItem = linearLayoutManager.findLastVisibleItemPosition();
Timber.e("totalItemCount: %s", totalItemCount);
Timber.e("lastVisibleItem: %s", lastVisibleItem);
if (!isLoading && totalItemCount <= (lastVisibleItem + 1)) {
Timber.i("End reached...");
if (onLoadMoreListener != null) {
//Log.i(TAG, "Episodes Adapter: onLoadMore calling...");
onLoadMoreListener.onLoadMore();
}
isLoading = true;
}
}
}
@Override
public void onScrollStateChanged(@NonNull RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
}
});
}
回收站:
private void setupRecycler() {
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getActivity());
recyclerView.setLayoutManager(linearLayoutManager);
historyAdapter = new HistoryAdapter(getActivity(), historyItems, recyclerView);
recyclerView.setAdapter(historyAdapter);
historyAdapter.setClickListener(this);
historyAdapter.setOnLoadMoreListener(this);
historyAdapter.setErrorClickListener(this);
}
我的回收站 xml:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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/header"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/medium_text_color_blue"
android:padding="12dp">
<TextView
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:gravity="start"
android:text="#"
android:textColor="@android:color/white"
android:textStyle="bold" />
<TextView
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="4.5"
android:gravity="start"
android:text="CLASS"
android:textAllCaps="true"
android:textColor="@android:color/white"
android:textStyle="bold" />
<TextView
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="2"
android:gravity="center"
android:text="Date"
android:textAllCaps="true"
android:textColor="@android:color/white"
android:textStyle="bold" />
<TextView
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="2"
android:gravity="center"
android:text="time"
android:textAllCaps="true"
android:textColor="@android:color/white"
android:textStyle="bold" />
</LinearLayout>
<FrameLayout
android:layout_below="@+id/header"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/no_reflection_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:visibility="gone"
android:layout_gravity="center"
android:text="No Reflection History found!" />
<androidx.recyclerview.widget.RecyclerView
android:id="@+id/history_recycler"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</FrameLayout>
</RelativeLayout>
我研究过的:
StackOverflow 上已经发布了许多这样的问题,但其中大多数都指向一个解决方案,即删除
ScrollView
的父 RecyclerView
阻止触发 onScrolled
方法,但这似乎不是我面临的问题。RecyclerView.onScrolled() not getting called
RecyclerView onScrolled not called when use scrollToPosition
RecyclerView onScrolled not being fired at all
RecyclerView not calling onScrolled at the bottom
android RecyclerView onScrolled not call
https://github.com/passsy/ArrayAdapter/issues/4
最佳答案
另一种方法是检查回收器是否可以垂直滚动,如果不能,则表示它已到达底部。
尝试这个
recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
@Override
override fun onScrollStateChanged(recyclerView: RecyclerView, newState: Int) {
super.onScrollStateChanged(recyclerView, newState)
if (!recyclerView.canScrollVertically(1)) {
// Load more
}
}
}
`
关于android - addOnScrollListener 的 RecyclerView onScrolled 方法只调用一次,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/59694298/