我正在列表中获取Json数据，其中包含100个项目。我将此列表传递给了recyclerview适配器。但是我首先只想通过10个项目。当用户滚动列表中的10个项目后，它应该从列表中加载更多数据。我已经实现了滚动侦听器和其他适配器。我不确定如何将json列表中的10个项目传递给适配器。
ScrollListener
public abstract class PaginationScrollListener extends RecyclerView.OnScrollListener {
LinearLayoutManager layoutManager;
/**
* Supporting only LinearLayoutManager for now.
*
* @param layoutManager
*/
public PaginationScrollListener(LinearLayoutManager layoutManager) {
this.layoutManager = layoutManager;
}
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
int visibleItemCount = layoutManager.getChildCount();
int totalItemCount = layoutManager.getItemCount();
int firstVisibleItemPosition = layoutManager.findFirstVisibleItemPosition();
if (!isLoading() && !isLastPage()) {
if ((visibleItemCount + firstVisibleItemPosition) >= totalItemCount
&& firstVisibleItemPosition >= 0
&& totalItemCount >= getTotalPageCount()) {
loadMoreItems();
}
}
}
protected abstract void loadMoreItems();
public abstract int getTotalPageCount();
public abstract boolean isLastPage();
public abstract boolean isLoading();
}
适配器
public class PaginationAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private static final int ITEM = 0;
private static final int LOADING = 1;
private List<Movie> movies;
private Context context;
private boolean isLoadingAdded = false;
public PaginationAdapter(Context context) {
this.context = context;
movies = new ArrayList<>();
}
public List<Movie> getMovies() {
return movies;
}
public void setMovies(List<Movie> movies) {
this.movies = movies;
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
RecyclerView.ViewHolder viewHolder = null;
LayoutInflater inflater = LayoutInflater.from(parent.getContext());
switch (viewType) {
case ITEM:
viewHolder = getViewHolder(parent, inflater);
break;
case LOADING:
View v2 = inflater.inflate(R.layout.item_progress, parent, false);
viewHolder = new LoadingVH(v2);
break;
}
return viewHolder;
}
@NonNull
private RecyclerView.ViewHolder getViewHolder(ViewGroup parent, LayoutInflater inflater) {
RecyclerView.ViewHolder viewHolder;
View v1 = inflater.inflate(R.layout.item_list, parent, false);
viewHolder = new MovieVH(v1);
return viewHolder;
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
Movie movie = movies.get(position);
switch (getItemViewType(position)) {
case ITEM:
MovieVH movieVH = (MovieVH) holder;
movieVH.textView.setText(movie.getTitle());
break;
case LOADING:
break;
}
}
@Override
public int getItemCount() {
return movies == null ? 0 : movies.size();
}
@Override
public int getItemViewType(int position) {
return (position == movies.size() - 1 && isLoadingAdded) ? LOADING : ITEM;
}
public void add(Movie mc) {
movies.add(mc);
notifyItemInserted(movies.size() - 1);
}
public void addAll(List<Movie> mcList) {
for (Movie mc : mcList) {
add(mc);
}
}
public void remove(Movie city) {
int position = movies.indexOf(city);
if (position > -1) {
movies.remove(position);
notifyItemRemoved(position);
}
}
public void clear() {
isLoadingAdded = false;
while (getItemCount() > 0) {
remove(getItem(0));
}
}
public boolean isEmpty() {
return getItemCount() == 0;
}
public void addLoadingFooter() {
isLoadingAdded = true;
add(new Movie());
}
public void removeLoadingFooter() {
isLoadingAdded = false;
int position = movies.size() - 1;
Movie item = getItem(position);
if (item != null) {
movies.remove(position);
notifyItemRemoved(position);
}
}
public Movie getItem(int position) {
return movies.get(position);
}
public MovieVH(View itemView) {
super(itemView);
textView = (TextView) itemView.findViewById(R.id.item_text);
}
}
protected class LoadingVH extends RecyclerView.ViewHolder {
public LoadingVH(View itemView) {
super(itemView);
}
}
}
**获得Api响应**
private void callApi() {
apiInterfacePages = ApiClient.getRetrofit().create(APIInterface.class);
Call<CamerasItem> camerasCall = apiInterfacePages.getCameras();
camerasCall.enqueue(new Callback<CamerasItem>() {
@Override
public void onResponse(Call<CamerasItem> call, Response<CamerasItem> response) {
CamerasItem camerasItem = response.body();
itemList = new ArrayList<>();
itemList = camerasItem.getItems();
Log.i("Item", "" + getChannel().getName());
for (int i = 0; i < itemList.size(); i++) {
if (itemList.get(i).getCategory().equals(getChannel().getName())){
if (!itemList.get(i).getUrlMjpeg().endsWith("=mediaRedirect")) {
String videoUrl = itemList.get(i).getUrlMjpeg();
String imageUrl = itemList.get(i).getThumbnail();
String name = itemList.get(i).getName();
String city = itemList.get(i).getCity();
String flag = itemList.get(i).getFlag();
String country= itemList.get(i).getCountry();
modelList.add(new MyModel(videoUrl, imageUrl, name, city, flag,country));
}
}
}
@Override
public void onFailure(Call<CamerasItem> call, Throwable t) {
Log.i("Item", "" + t.getMessage());
}
});
}
因此，现在如何第一次将10个项目传递给recyclerview，并在每次滚动时传递10个项目。
答案 0 :(得分：0)
您必须在定义/usr/share/logstash/bin/logstash-plugin install --no-verify --version 1.1.0 logstash-input-azure_event_hubs
Installing logstash-input-azure_event_hubs
Plugin not found, aborting
ERROR: Installation Aborted, message: Could not find gem 'logstash-input-azureeventhub (= 1.1.0) java' in any of the gem sources listed in your Gemfile or installed on this machine.
的活动xml中设置Progressbar。
loadThumbnail是下载缩略图的功能。向下滚动只会带来一点延迟。现在，适配器类的完整代码如下
Recyclerviewxml文件的代码
public class CamerasAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private List<MyModel> list;
private Activity mActivity;
private static final int TYPE_VIDEO = 0, TYPE_ADD = 1;
private static final int PAGE_LIMIT = 5;
private int mCurrentLimit = PAGE_LIMIT;
private boolean mIsLoading;
RelativeLayout mLoaderProgress;
public CamerasAdapter(FragmentActivity activity, RelativeLayout loaderLayout) {
mActivity = activity;
mLoaderProgress = loaderLayout;
}
@NonNull
@Override
public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
View itemView = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.li_web_cam_view, viewGroup, false);
return new CamsViewHolder(itemView);
}
@Override
public void onBindViewHolder(@NonNull RecyclerView.ViewHolder viewHolder, int i) {
if (mCurrentLimit == (i + 1) && mCurrentLimit <= list.size() && !mIsLoading) {
mLoaderProgress.setVisibility(View.VISIBLE);
mIsLoading = true;
loadThumbnail(0, i + 1);
} else {
//do nothing
}
((CamsViewHolder) viewHolder).onBindData(mActivity, list.get(i), i);
((CamsViewHolder) viewHolder).emptyView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
itemClickListner.onClick(i, ((CamsViewHolder) viewHolder).tvCamName, list.get(i));
}
});
}
private void loadThumbnail(final int count, int position) {
try {
if (count > 2 || position >= list.size()) {
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
mIsLoading = false;
mCurrentLimit = mCurrentLimit + PAGE_LIMIT;
notifyItemChanged(position - count);
mLoaderProgress.setVisibility(View.GONE);
return;
}
}, 2000);
} else {
if (list.get(position) == null) {
loadThumbnail(count, position + 1);
} else {
Glide.with(mActivity).load(list.get(position).getImage_url()).downloadOnly(new SimpleTarget<File>() {
@Override
public void onResourceReady(File resource, GlideAnimation<? super File> glideAnimation) {
loadThumbnail((count + 1), (position + 1));
}
@Override
public void onLoadFailed(Exception e, Drawable errorDrawable) {
loadThumbnail((count + 1), (position + 1));
}
});
}
}
} catch (Exception e) {
e.printStackTrace();
mLoaderProgress.setVisibility(View.GONE);
mIsLoading = false;
}
}
@Override
public int getItemCount() {
return mCurrentLimit <= list.size() ? mCurrentLimit : list.size();
}
public void setData(List<MyModel> dataList) {
this.list = dataList;
notifyDataSetChanged();
}
ItemClickListner itemClickListner;
public void setListener(ItemClickListner listener) {
itemClickListner = listener;
}
ProgressLoadListener progressLoadListener;
public void setProgressLoadListener(ProgressLoadListener listener) {
progressLoadListener = listener;
}
}
使用适配器初始化Recyclerview
<android.support.v7.widget.RecyclerView
android:id="@+id/recycler_view"
android:layout_width="match_parent"
android:visibility="gone"
android:layout_height="match_parent"
android:layout_above="@+id/loader_progress_bar_layout"
android:background="#f5f5f5"
android:layout_gravity="center" />
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:id="@+id/loader_progress_bar_layout"
android:visibility="gone"
android:background="#fff"
>
<ProgressBar
android:id="@+id/progress_bar_loader"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_gravity="center" />
</RelativeLayout>