如何在Fragment ListView中将scoll上的json数据提取到底部 [英] How to fetch json data on scoll to bottom in Fragment ListView

问题描述

我想在listview中获取10条记录，并在滚动到底部时获取其他记录.我是新来的，请帮助我.这是我的Java代码和适配器片段:

I want to fetch 10 records in listview and other records fetch on scroll to bottom. I'm a new in this please help me. Here's my fragment of Java code and adapter:

Latest_Fragment.java

private static final String TAG = LatestFragment.class.getSimpleName();

// Movies json url
private static final String url = "http://abc.news/android/lastest.php?page=1";
private ProgressDialog pDialog;
private List<Movie> movieList = new ArrayList<Movie>();

private List<Movie> additems;
private ListView listView;
private CustomListAdapter adapter;
boolean flag_loading = true;

private static String Title="title";
private static String Genre="genre";
private static String Rating="rating";
private static String Sec_id="secid";
private static String Category="category";
private static String bitmap="thumbnailUrl";
ListView list;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {


    View v = inflater.inflate(R.layout.latest_layout, container, false);
    //getActivity().getActionBar().setDisplayHomeAsUpEnabled(true);
    Intent intent2 = new Intent();
    getActivity().setResult(Activity.RESULT_OK, intent2);

    list = (ListView) v.findViewById(R.id.list);


    adapter = new CustomListAdapter(getActivity(), movieList);
    list.setAdapter(adapter);



       pDialog = new ProgressDialog(getActivity());
    // Showing progress dialog before making http request
    pDialog.setMessage("Loading...");
    pDialog.show();





    // Creating volley request obj
    JsonArrayRequest movieReq = new JsonArrayRequest(url,
            new Response.Listener<JSONArray>() {

                @Override
                public void onResponse(JSONArray response) {
                    Log.d(TAG, response.toString());
                    hidePDialog();
                  //  flag_loading = false;
                    // Parsing json

                    for (int i = 0; i < response.length(); i++) {
                        try {

                            JSONObject obj = response.getJSONObject(i);
                            Movie movie = new Movie();

                            movie.setSec_id(obj.getString("sec_id"));
                            movie.setCategory(obj.getString("category"));
                            movie.setTitle(obj.getString("title"));
                            movie.setThumbnailUrl(obj.getString("image"));
                            movie.setRating(obj.getString("rating"));
                            //   movie.setYear(obj.getString("releaseYear"));
                            movie.setGenre(obj.getString("genre"));

                            // Genre is json array


                            // adding movie to movies array

                            movieList.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) {
            if (error instanceof NoConnectionError){
                Toast.makeText(getActivity().getBaseContext(), "Bummer..There's No Internet connection!", Toast.LENGTH_LONG).show();

            }

        }
    });




    // Adding request to request queue
    AppController.getInstance().addToRequestQueue(movieReq);

    list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view,
                                int position, long id) {

            Intent intent = new Intent(getActivity(), News_Detail.class);

            bitmap = ((Movie)movieList.get(position)).getThumbnailUrl();
            intent.putExtra("images", bitmap);

            final String names = ((TextView) view.findViewById(R.id.title)).getText().toString();
            intent.putExtra(Title, names);

            String genredescription = ((TextView) view.findViewById(R.id.genre)).getText().toString(); //must for send data
            intent.putExtra(Genre, genredescription);

            String date = ((TextView) view.findViewById(R.id.rating)).getText().toString();
            intent.putExtra(Rating, date);
            startActivity(intent);



        }


    });



    return v;


}





@Override
public void onDestroy() {
    super.onDestroy();
    hidePDialog();
}

private void hidePDialog() {
    if (pDialog != null) {
        pDialog.dismiss();
        pDialog = null;
    }
}


public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getActivity().getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}


}

customlistadapter.java

private Activity activity;
private LayoutInflater inflater;
private List<Movie> movieItems;
ImageLoader imageLoader = AppController.getInstance().getImageLoader();
public CustomListAdapter(Activity activity, List<Movie> movieItems) {
    this.activity = activity;
    this.movieItems = movieItems;
}

@Override
public int getCount() {
    return movieItems.size();
}

@Override
public Object getItem(int location) {
    return movieItems.get(location);
}

@Override
public long getItemId(int position) {
    return position;
}

// first row layout change below code is working
@Override
public int getViewTypeCount() {     return 2;   }

//if remove below code then chage layout randomly
@Override
public int getItemViewType(int position) {
    if (position == 0) {
        return 0;
    } else {
        return 1;
    }
}

// first row layout change above code is working

@Override
public View getView(int position, View convertView, ViewGroup parent) {





    if (inflater == null)
        inflater = (LayoutInflater) activity
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    if (convertView == null)

        if(position == 0) {
            convertView = inflater.inflate(R.layout.list_row2, null);
        }else
        {
            convertView = inflater.inflate(R.layout.list_row, null);
        }

    if (imageLoader == null)
        imageLoader = AppController.getInstance().getImageLoader();


    NetworkImageView thumbNail = (NetworkImageView) convertView.findViewById(R.id.thumbnail);
    final       TextView sec_id = (TextView) convertView.findViewById(R.id.sec_id);
    final TextView category = (TextView) convertView.findViewById(R.id.category);
    TextView title = (TextView) convertView.findViewById(R.id.title);
    TextView rating = (TextView) convertView.findViewById(R.id.rating);
    TextView genre = (TextView) convertView.findViewById(R.id.genre);
    //TextView year = (TextView) convertView.findViewById(R.id.releaseYear);





    // getting movie data for the row
    Movie m = movieItems.get(position);

    // thumbnail image
    thumbNail.setImageUrl(m.getThumbnailUrl(), imageLoader);

    // title
    title.setText(m.getTitle());

    // rating
    rating.setText(m.getRating());

    // genre

    genre.setText(m.getGenre());

    sec_id.setText(m.getSec_id());

    category.setText(m.getCategory());





    // release year
    //  year.setText(m.getYear());

    ImageView btn = (ImageView) convertView.findViewById(R.id.share);
    btn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent(android.content.Intent.ACTION_SEND);
            intent.setType("text/plain");
            intent.putExtra(Intent.EXTRA_TEXT,  "\n" + "\n" + "http://vasundharadeep.news/News/"+sec_id.getText().toString()+"/"+category.getText().toString());
            activity.startActivity(intent);

        }
    });


    return convertView;

}




}

推荐答案

在代码下方查看

    public class MyFragment extends Fragment implements     OnScrollListener {
 private ListView listView;
 private ArrayList<DataModel> dataList = new ArrayList<DataModel>();
 private boolean mHasRequestedMore;

onCreateView(…..){
listView  = view.findViewById();
listView.setonScrollLestener(this);
callWebservice();
}





@Override
public void onScroll(final AbsListView view, final int firstVisibleItem, final int visibleItemCount, final int totalItemCount) {
if (!mHasRequestedMore) {
    int lastInScreen = firstVisibleItem + visibleItemCount;
    if (lastInScreen >= totalItemCount) {
         mHasRequestedMore = true;
    callWebservice();
    }
}
}
@Override
 public void onScrollStateChanged(AbsListView view, int scrollState{}       

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