Android：分页下载示例(PullToRefresh)

此篇文章注释较少（下载数据使用的是Volley），如若有不解之处，
可以参考另一篇博客（下载数据使用的是Xutils）：
《PullToRefresh下拉刷新，上拉分页，返回顶部》

package com.myapplication.newpagerrefreshlistview;import android.os.AsyncTask;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.text.TextUtils;import android.widget.ListView;import com.alibaba.fastjson.JSON;import com.alibaba.fastjson.JSONArray;import com.alibaba.fastjson.JSONObject;import com.handmark.pulltorefresh.library.ILoadingLayout;import com.handmark.pulltorefresh.library.PullToRefreshBase;import com.handmark.pulltorefresh.library.PullToRefreshListView;import com.myapplication.newpagerrefreshlistview.VolleyUtils.MyDataUtils;import com.myapplication.newpagerrefreshlistview.VolleyUtils.StringCallBack;import com.myapplication.newpagerrefreshlistview.VolleyUtils.VolleyUtils;import org.json.JSONException;import java.util.ArrayList;import java.util.List;public class MainActivity extends AppCompatActivity {    private PullToRefreshListView pullToRefreshListView;    private String path = "http://api.fengniao.com/app_ipad/pic_bbs_list_v2." +            "php?appImei=99000505856649&osType=Android&osVersion=4.1.1&fid=125&page=";    //封装好的下载工具    private VolleyUtils volleyUtils;    private List<Bean> totallist = new ArrayList<>();    private ListViewAdapter listViewAdapter;    private int page = 1;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        init();        getData(1);        setPullListener();    }    private void init() {        volleyUtils = new VolleyUtils();        pullToRefreshListView = (PullToRefreshListView) findViewById(R.id.refresh_to_update_next_pager);        //先设置拉动模式(常见3种),        pullToRefreshListView.setMode(PullToRefreshBase.Mode.BOTH);        //设置刷新界面,拿到刷新界面        ILoadingLayout loadingLayout = pullToRefreshListView.getLoadingLayoutProxy(true, true);        //设置加载时候的图片        loadingLayout.setLoadingDrawable(getResources().getDrawable(R.mipmap.ic_launcher));        //最近更新，一般还要设置更新时间        loadingLayout.setLastUpdatedLabel(MyDataUtils.getCurrentDate());        //设置刷新时候的文字        loadingLayout.setRefreshingLabel("拼命加载中，莫捉急……");        //设置拉动和释放时候的文字        loadingLayout.setPullLabel("轻一点拉动，爱护屏幕……");        loadingLayout.setRefreshingLabel("释放中……");        listViewAdapter = new ListViewAdapter(this, totallist);        pullToRefreshListView.setAdapter(listViewAdapter);    }    private void setPullListener() {        pullToRefreshListView.setOnRefreshListener(                new PullToRefreshBase.OnRefreshListener2<ListView>() {                    @Override                    public void onPullDownToRefresh(PullToRefreshBase<ListView> refreshView) {                        //TODo 下拉时触发的事件                        new GetDataTask().execute();//不加此行，刷新不会停止，有bug待解决                    }                    @Override                    public void onPullUpToRefresh(PullToRefreshBase<ListView> refreshView) {                        //TODO 上拉时触发的事件                        page++;                        getData(page);                        new GetDataTask().execute();//不加此行，刷新不会停止，有bug待解决                    }                });    }    public void getData(int page) {        volleyUtils.getStringData(path + page, new StringCallBack() {            @Override            public void getStringData(String data) {                //TODO json解析                //jsonToList(data);                fastJsonToList(data);            }        });    }    List<Bean> fastJsonToList(String s) {        if (!TextUtils.isEmpty(s)) {            JSONObject json = JSON.parseObject(s);            JSONArray array = json.getJSONArray("list");            List<Bean> list = JSON.parseArray(array.toJSONString(), Bean.class);            totallist.addAll(list);            listViewAdapter.notifyDataSetChanged();            if (list.size() != 0) {                return list;            }        }        return null;    }    List<Bean> jsonToList(String s) {        List<Bean> list = new ArrayList<>();        try {            org.json.JSONObject object = new org.json.JSONObject(s);            org.json.JSONArray array = object.getJSONArray("list");            for (int i = 0; i < array.length(); i++) {                org.json.JSONObject j = array.getJSONObject(i);                String pic_url = j.getString("pic_url");                String title = j.getString("title");                Bean bean = new Bean();                bean.setPic_url(pic_url);                bean.setTitle(title);                list.add(bean);            }            totallist.addAll(list);            listViewAdapter.notifyDataSetChanged();        } catch (JSONException e) {            e.printStackTrace();        }        return list;    }    private class GetDataTask extends AsyncTask<Void, Void, List<Bean>> {        @Override        protected List<Bean> doInBackground(Void... params) {            try {                Thread.sleep(4000);            } catch (InterruptedException e) {            }            return totallist;        }        @Override        protected void onPostExecute(List<Bean> result) {            listViewAdapter.notifyDataSetChanged();            pullToRefreshListView.onRefreshComplete();            super.onPostExecute(result);        }    }}

ListViewAdapter中代码：

package com.myapplication.newpagerrefreshlistview;import android.content.Context;import android.graphics.Bitmap;import android.view.View;import android.view.ViewGroup;import android.widget.ImageView;import android.widget.TextView;import com.myapplication.newpagerrefreshlistview.VolleyUtils.BitmapCallBack;import java.util.List;/** * Created by Administrator on 2016/3/8. */public class ListViewAdapter extends MyBaseAdapter<Bean> {    public ListViewAdapter(Context context, List<Bean> list) {        super(context, list);    }    @Override    public View getItemView(int position, View convertView, ViewGroup parent) {        final ViewHolder viewHolder;        if (convertView == null) {            convertView = inflater.inflate(R.layout.item, parent, false);            viewHolder = new ViewHolder();            viewHolder.img = (ImageView) convertView.findViewById(R.id.iv_item_pic);            viewHolder.txt = (TextView) convertView.findViewById(R.id.tv_item_txt);            convertView.setTag(viewHolder);        } else {            viewHolder = (ViewHolder) convertView.getTag();        }        //数据显示        Bean bean = list.get(position);        viewHolder.txt.setText(bean.getTitle());        utils.getImageBitmap(bean.getPic_url(), new BitmapCallBack() {            @Override            public void getBitmap(Bitmap bitmap) {                viewHolder.img.setImageBitmap(bitmap);            }        });        return convertView;    }    class ViewHolder {        ImageView img;        TextView txt;    }}