这是破旧。我创建了一个滑动选项卡应用程序，并在每个片段上包含json。我正在尝试实现Endless Scroll Listener：https://github.com/codepath/android_guides/wiki/Endless-Scrolling-with-AdapterViews，以便在加载时向列表视图中显示只有一定数量的项目，并且当您向下滚动时会出现更多项目。
然而，我被卡住了。我不确定如何实现/使用这个类（public boolean onLoadMore（int page，int totalItemsCount）等）。我在stackoverflow中读到了另一篇关于此的帖子，但我无法弄清楚如何使它工作。任何有关如何使用它的建议或想法将不胜感激。
我包含了我的列表适配器，我的一个片段，endlessrollisterner类。我最初的尝试是在此行之后的public void onActivityCreated中包含此方法：listView =（ListView）getView（）。findViewById（R.id.list）;
EndlessScrollListener：
import android.widget.AbsListView;
public abstract class EndlessScrollListener implements AbsListView.OnScrollListener {
// The minimum amount of items to have below your current scroll position
// before loading more.
private int visibleThreshold = 5;
// 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;
public EndlessScrollListener() {
}
public EndlessScrollListener(int visibleThreshold) {
this.visibleThreshold = visibleThreshold;
}
public EndlessScrollListener(int visibleThreshold, int startPage) {
this.visibleThreshold = visibleThreshold;
this.startingPageIndex = startPage;
this.currentPage = startPage;
}
// 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 onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount)
{
// 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;
currentPage++;
}
// 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.
if (!loading && (totalItemCount - visibleItemCount)<=(firstVisibleItem + visibleThreshold)) {
loading = onLoadMore(currentPage + 1, totalItemCount);
}
}
// Defines the process for actually loading more data based on page
// Returns true if more data is being loaded; returns false if there is no more data to load.
public abstract boolean onLoadMore(int page, int totalItemsCount);
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
// Don't take any action on changed
}
}
CustomListAdapter代码：
public class CustomListAdapter extends BaseAdapter {
private Activity activity;
private LayoutInflater inflater;
private List<Tanga> tangasItems;
ImageLoader imageLoader = AppController.getInstance().getImageLoader();
public CustomListAdapter(Activity activity, List<Tanga> movieItems) {
this.activity = activity;
this.tangasItems = movieItems;
}
@Override
public int getCount() {
return tangasItems.size();
}
@Override
public Object getItem(int location) {
return tangasItems.get(location);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if (inflater == null)
inflater = (LayoutInflater) activity
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if (convertView == null)
convertView = inflater.inflate(R.layout.list_row, null);
TextView name = (TextView) convertView.findViewById(R.id.name);
// getting movie data for the row
Tanga m = tangasItems.get(position);
// title
name.setText(m.getName());
return convertView;
}
}
片段：
public class Tab1 extends Fragment {
private static final String url = "website.json";
private List<Tanga> tangaList = new ArrayList<Tanga>();
private ListView listView;
private CustomListAdapter adapter;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
public void onActivityCreated (Bundle savedInstanceState){
super.onActivityCreated(savedInstanceState);
listView = (ListView) getView().findViewById(R.id.list);
adapter = new CustomListAdapter(getActivity(), tangaList);
listView.setAdapter(adapter);
JsonArrayRequest movieReq = new JsonArrayRequest(url,
new Response.Listener<JSONArray>() {
@Override
public void onResponse(JSONArray response) {
// Parsing json
for (int i = 0; i < response.length(); i++) {
try {
JSONObject obj = response.getJSONObject(i);
Tanga movie = new Tanga();
//name
String name = obj.getString("name");
movie.setName(name);
// adding movie to movies array
tangaList.add(movie);
} catch (JSONException e) {
e.printStackTrace();
}
}
// notifying list adapter about data changes
// so that it renders the list view with updated data
adapter.notifyDataSetChanged();
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d("Error: ");
}
});
// Adding request to request queue
AppController.getInstance().addToRequestQueue(movieReq);
}
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.tabs, container, false);
return v;
}
}