用Recyclerview的10个项目加载10个项目

Question

从JSON文件中，我几乎得到了(200-300图像URL(，我试图逐10个图像加载10个图像，以使图像快速加载，而不是一次加载所有图像(200-300(。但我遇到了一个问题RecyclerView在前10个项目后停止滚动，以下是我尝试过的：

InfiniteCrollListener.java

private void initInfiniteScrollListener(LinearLayoutManager mLayoutManager) {
infiniteScrollListener = new InfiniteScrollListener(mLayoutManager) {
@Override
public void onLoadMore(int page) {
pb.setVisibility(View.VISIBLE);
refreshContent();
}
};
recyclerView.addOnScrollListener(infiniteScrollListener);
}

---

设置适配器的方法：

private void refreshContent() {
fetchRemoteData(new DataStatus() {
@Override
public void onSuccess(List<Post> posts) {
loading.setVisibility(View.GONE);
pb.setVisibility(View.GONE);
if (adapter == null) {
adapter = new MyAdapter(posts, getActivity(), new RecyclerViewClickListener() {
@Override
public void onClick(View view, Post post) {
}
});
recyclerView.setAdapter(adapter);
} else {
int position = adapter.getItemCount();
adapter.getItems().addAll(posts);
adapter.notifyItemRangeInserted(position, position + 10);
}
}
@Override
public void onError(Exception e) {
slowinternetconnection();
}
});
}

获取数据：

private void fetchRemoteData(final DataStatus callback) {
StringRequest stringRequest = new StringRequest(Request.Method.GET,
URL_DATA,
new Response.Listener<String>() {
@Override
public void onResponse(String s) {
List<Post> listItems = new ArrayList<>();
List<Post> PagintationList = new ArrayList<>();
try {
JSONObject jsonObject = new JSONObject(s);
JSONArray array = jsonObject.getJSONArray("bgs");
for (int i = 0; i < array.length(); i++) {
JSONObject o = array.getJSONObject(i);
Post item = new Post(
o.optString("img"),
o.optString("name")
);
listItems.add(item);
}
for (int count = resetNumber; count < 10; count++) {
PagintationList.add(listItems.get(count));
}
resetNumber = PagintationList.size() + 1;
callback.onSuccess(PagintationList);
} catch (JSONException e) {
slowinternetconnection();
}
}
},
new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
callback.onError(error);
}
});
RequestQueue requestQueue = Volley.newRequestQueue(getActivity().getApplicationContext());
stringRequest.setShouldCache(false);
requestQueue.getCache().clear();
requestQueue.add(stringRequest);
}

我想要的是：

例如，从250张图像开始，我想每次用户滚动循环查看时加载10张图像，直到250张图像完成

Answer 1

private void populateData() {
int i = 0;
while (i < 10) {
rowsArrayList.add("Item " + i);
i++;
}
}
private void initAdapter() {
recyclerViewAdapter = new RecyclerViewAdapter(rowsArrayList);
recyclerView.setAdapter(recyclerViewAdapter);
}
private void initScrollListener() {
recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
@Override
public void onScrollStateChanged(@NonNull RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
}
@Override
public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
LinearLayoutManager linearLayoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
if (!isLoading) {
if (linearLayoutManager != null && linearLayoutManager.findLastCompletelyVisibleItemPosition() == rowsArrayList.size() - 1) {
//bottom of list!
loadMore();
isLoading = true;
}
}
}
});

}
private void loadMore() {
rowsArrayList.add(null);
recyclerViewAdapter.notifyItemInserted(rowsArrayList.size() - 1);

Handler handler = new Handler();
handler.postDelayed(new Runnable() {
@Override
public void run() {
rowsArrayList.remove(rowsArrayList.size() - 1);
int scrollPosition = rowsArrayList.size();
recyclerViewAdapter.notifyItemRemoved(scrollPosition);
int currentSize = scrollPosition;
int nextLimit = currentSize + 10;
while (currentSize - 1 < nextLimit) {
rowsArrayList.add("Item " + currentSize);
currentSize++;
}
recyclerViewAdapter.notifyDataSetChanged();
isLoading = false;
}
}, 2000);

}

在适配器类中

公共类RecyclerViewAdapter扩展了RecyclerView。Adapter｛

private final int VIEW_TYPE_ITEM = 0;
private final int VIEW_TYPE_LOADING = 1;
public List<String> mItemList;

public RecyclerViewAdapter(List<String> itemList) {
mItemList = itemList;
}
@NonNull
@Override
public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
if (viewType == VIEW_TYPE_ITEM) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_row, parent, false);
return new ItemViewHolder(view);
} else {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_loading, parent, false);
return new LoadingViewHolder(view);
}
}
@Override
public void onBindViewHolder(@NonNull RecyclerView.ViewHolder viewHolder, int position) {
if (viewHolder instanceof ItemViewHolder) {
populateItemRows((ItemViewHolder) viewHolder, position);
} else if (viewHolder instanceof LoadingViewHolder) {
showLoadingView((LoadingViewHolder) viewHolder, position);
}
}
@Override
public int getItemCount() {
return mItemList == null ? 0 : mItemList.size();
}
/**
* The following method decides the type of ViewHolder to display in the RecyclerView
*
* @param position
* @return
*/
@Override
public int getItemViewType(int position) {
return mItemList.get(position) == null ? VIEW_TYPE_LOADING : VIEW_TYPE_ITEM;
}

private class ItemViewHolder extends RecyclerView.ViewHolder {
TextView tvItem;
public ItemViewHolder(@NonNull View itemView) {
super(itemView);
tvItem = itemView.findViewById(R.id.tvItem);
}
}
private class LoadingViewHolder extends RecyclerView.ViewHolder {
ProgressBar progressBar;
public LoadingViewHolder(@NonNull View itemView) {
super(itemView);
progressBar = itemView.findViewById(R.id.progressBar);
}
}
private void showLoadingView(LoadingViewHolder viewHolder, int position) {
//ProgressBar would be displayed
}
private void populateItemRows(ItemViewHolder viewHolder, int position) {
String item = mItemList.get(position);
viewHolder.tvItem.setText(item);
}

查看此链接https://www.journaldev.com/24041/android-recyclerview-load-more-endless-scrolling

您可以先加载10个项目，然后刷新并加载下一个10个项目。