我正在尝试创建一个可以加载500个项目的recyclerview，这就是为什么我要对它进行分页，以便不会立即加载500个以上的项目列表。
我的适配器：
public class MenuListsAdapter extends RecyclerView.Adapter<MenuListsAdapter.ViewHolder> {
// Store a member variable for the contacts
private List<MenuList> menuList;
// Pass in the contact array into the constructor
public MenuListsAdapter(List<MenuList> contacts) {
menuList = contacts;
}
// Provide a direct reference to each of the views within a data item
// Used to cache the views within the item layout for fast access
public static class ViewHolder extends RecyclerView.ViewHolder {
// Your holder should contain a member variable
// for any view that will be set as you render a row
public TextView txtDesc;
// We also create a constructor that accepts the entire item row
// and does the view lookups to find each subview
public ViewHolder(View itemView) {
// Stores the itemView in a public final member variable that can be used
// to access the context from any ViewHolder instance.
super(itemView);
txtDesc = (TextView) itemView.findViewById(R.id.txtDesc);
}
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
Context context = parent.getContext();
LayoutInflater inflater = LayoutInflater.from(context);
View contactView = inflater.inflate(R.layout.menulistview_layout, parent, false);
ViewHolder viewHolder = new ViewHolder(contactView);
return viewHolder;
}
@Override
public void onBindViewHolder(ViewHolder viewHolder, int position) {
MenuList contact = menuList.get(position);
TextView textView = viewHolder.txtDesc;
textView.setText(contact.getTxtDesc());
}
@Override
public int getItemCount() {
return menuList.size();
}
}
My EndlessRecyclerScrollListener：
public abstract class EndlessRecyclerViewScrollListener extends RecyclerView.OnScrollListener {
// The minimum amount of items to have below your current scroll position
// before loading more.
private int visibleThreshold = 8;
// The current offset index of data you have loaded
private int currentPage = 0;
// The total number of items in the dataset after the last load
private int previousTotalItemCount = 0;
// True if we are still waiting for the last set of data to load.
private boolean loading = true;
// Sets the starting page index
private int startingPageIndex = 0;
RecyclerView.LayoutManager mLayoutManager;
public EndlessRecyclerViewScrollListener(LinearLayoutManager layoutManager) {
this.mLayoutManager = layoutManager;
}
public EndlessRecyclerViewScrollListener(GridLayoutManager layoutManager) {
this.mLayoutManager = layoutManager;
visibleThreshold = visibleThreshold * layoutManager.getSpanCount();
}
public EndlessRecyclerViewScrollListener(StaggeredGridLayoutManager layoutManager) {
this.mLayoutManager = layoutManager;
visibleThreshold = visibleThreshold * layoutManager.getSpanCount();
}
public int getLastVisibleItem(int[] lastVisibleItemPositions) {
int maxSize = 0;
for (int i = 0; i < lastVisibleItemPositions.length; i++) {
if (i == 0) {
maxSize = lastVisibleItemPositions[i];
}
else if (lastVisibleItemPositions[i] > maxSize) {
maxSize = lastVisibleItemPositions[i];
}
}
return maxSize;
}
// This happens many times a second during a scroll, so be wary of the code you place here.
// We are given a few useful parameters to help us work out if we need to load some more data,
// but first we check if we are waiting for the previous load to finish.
@Override
public void onScrolled(RecyclerView view, int dx, int dy) {
int lastVisibleItemPosition = 0;
int totalItemCount = mLayoutManager.getItemCount();
if (mLayoutManager instanceof StaggeredGridLayoutManager) {
int[] lastVisibleItemPositions = ((StaggeredGridLayoutManager) mLayoutManager).findLastVisibleItemPositions(null);
// get maximum element within the list
lastVisibleItemPosition = getLastVisibleItem(lastVisibleItemPositions);
} else if (mLayoutManager instanceof LinearLayoutManager) {
lastVisibleItemPosition = ((LinearLayoutManager) mLayoutManager).findLastVisibleItemPosition();
} else if (mLayoutManager instanceof GridLayoutManager) {
lastVisibleItemPosition = ((GridLayoutManager) mLayoutManager).findLastVisibleItemPosition();
}
// If the total item count is zero and the previous isn't, assume the
// list is invalidated and should be reset back to initial state
if (totalItemCount < previousTotalItemCount) {
this.currentPage = this.startingPageIndex;
this.previousTotalItemCount = totalItemCount;
if (totalItemCount == 0) {
this.loading = true;
}
}
// If it’s still loading, we check to see if the dataset count has
// changed, if so we conclude it has finished loading and update the current page
// number and total item count.
if (loading && (totalItemCount > previousTotalItemCount)) {
loading = false;
previousTotalItemCount = totalItemCount;
}
// If it isn’t currently loading, we check to see if we have breached
// the visibleThreshold and need to reload more data.
// If we do need to reload some more data, we execute onLoadMore to fetch the data.
// threshold should reflect how many total columns there are too
if (!loading && (lastVisibleItemPosition + visibleThreshold) > totalItemCount) {
currentPage++;
onLoadMore(currentPage, totalItemCount);
loading = true;
}
}
// Defines the process for actually loading more data based on page
public abstract void onLoadMore(int page, int totalItemsCount);
}
My Fragment在OnCreateView方法中生成RecyclerView的地方：
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_menu, container, false);
//genDummyItems();
menuRV = (RecyclerView) view.findViewById(R.id.menuRV);
final List<MenuList> allContacts = MenuList.createMenuList(100, 0);
adapter = new MenuListsAdapter(allContacts);
menuRV.setAdapter(adapter);
mLayoutManager = new LinearLayoutManager(getContext());
menuRV.setLayoutManager(mLayoutManager);
menuRV.addOnScrollListener(new EndlessRecyclerViewScrollListener(mLayoutManager) {
@Override
public void onLoadMore(int page, int totalItemsCount) {
List<MenuList> moreContacts = MenuList.createMenuList(10, 0);
int curSize = adapter.getItemCount();
allContacts.addAll(moreContacts);
adapter.notifyItemRangeInserted(curSize, allContacts.size() - 1);
}
});
return view;
}
Recycler View正在闪烁onScroll，请指导我所缺少的内容，以便我能够正确地制作无尽的回收商。