XlistView 加载头部ViewPager 网络请求数据 存入数据库

public class MainActivity extends AppCompatActivity {    private XListView xlv;    List<Da.StoriesBean> list;    private ViewPager vp3;    private List<ImageView> viewList;    private Da da;    private View view;    // 线程    Handler handler = new Handler(){        @Override        public void handleMessage(Message msg) {            super.handleMessage(msg);        }    };    private BeanDao dao;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        // 找控件        xlv = (XListView) findViewById(R.id.xlv3);        list = new ArrayList<Da.StoriesBean>();        // 实例化dao        dao =   new BeanDao(this);        // 初始化数据        initData();        // 找控件并加载头部布局        view = View.inflate(MainActivity.this, R.layout.vp3_item,null);        xlv.addHeaderView(view);        // 设置允许下拉  上拉        xlv.setPullRefreshEnable(true);        xlv.setPullLoadEnable(true);        // 监听事件        xlv.setXListViewListener(new XListView.IXListViewListener() {            @Override            public void onRefresh() {                handler.postDelayed(new Runnable() {                    @Override                    public void run() {                        initData();                        xlv.stopRefresh();                    }                },3000);            }            @Override            public void onLoadMore() {                handler.postDelayed(new Runnable() {                    @Override                    public void run() {                        initData();                        xlv.stopLoadMore();                    }                },3000);            }        });    }    private void initData() {        // 异步任务        new AsyncTask<String,Integer,String>(){            @Override            protected void onPostExecute(String s) {                MyAdapter adapter = new MyAdapter();                xlv.setAdapter(adapter);                // 把返回的view赋值给初始化数据的方法                view = initViewPager();                // 添加数据库                dao.addSb(da.getStories());                dao.addTb(da.getTop_stories());                super.onPostExecute(s);            }            @Override            protected String doInBackground(String... strings) {                getData();                ImageLoaderConfiguration configuration = ImageLoaderConfiguration.createDefault(MainActivity.this);                ImageLoader.getInstance().init(configuration);                return null;            }        }.execute();    }    private View initViewPager() {        vp3 = view.findViewById(R.id.vp3);        getViewData();        MyPagerAdaPter myPagerAdaPter = new MyPagerAdaPter();        vp3.setAdapter(myPagerAdaPter);        final TextView vp3_tv = view.findViewById(R.id.vp3_tv);        if(da != null){            // 设置ViewPager上面的文字            vp3_tv.setText(da.getTop_stories().get(0).getTitle());        }        vp3.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {            @Override            public void onPageScrolled(int i, float positionOffset, int positionOffsetPixels) {                // 文字跟着图片变换                vp3_tv.setText(da.getTop_stories().get(i).getTitle());            }            @Override            public void onPageSelected(int position) {            }            @Override            public void onPageScrollStateChanged(int state) {            }        });        return view;    }    private void getViewData() {        viewList = new ArrayList<ImageView>();        if(da != null){            // 如果da不等于空   遍历Top  循环添加图片            for (int i = 0; i <da.getTop_stories().size() ; i++) {                ImageView iv = new ImageView(MainActivity.this);                iv.setScaleType(ImageView.ScaleType.FIT_XY);                ImageLoader.getInstance().displayImage(da.getTop_stories().get(i).getImage(),iv);                viewList.add(iv);            }        }    }    private void getData() {        try {            // 网络请求数据            URL url = new URL("https:/");            HttpURLConnection conn = (HttpURLConnection) url.openConnection();            conn.setRequestMethod("GET");            int code = conn.getResponseCode();            if(code == 200){                Gson gson = new Gson();                da = gson.fromJson(new InputStreamReader(conn.getInputStream(),"UTF-8"),Da.class);                list = da.getStories();            }        } catch (Exception e) {            e.printStackTrace();        }    }    class MyAdapter extends BaseAdapter{        @Override        public int getCount() {            return list.size();        }        @Override        public Object getItem(int i) {            return list.get(i);        }        @Override        public long getItemId(int i) {            return i;        }        @Override        public View getView(int i, View view, ViewGroup viewGroup) {            ViewHolder holder;            if(view == null){                holder = new ViewHolder();                view = View.inflate(MainActivity.this,R.layout.xlv_item,null);                holder.xlv3_image = view.findViewById(R.id.xlv3_image);                holder.xlv3_title = view.findViewById(R.id.xlv3_title);                view.setTag(holder);            }else{                holder = (ViewHolder) view.getTag();            }            holder.xlv3_title.setText(list.get(i).getTitle());            ImageLoader.getInstance().displayImage(list.get(i).getImages().get(0),holder.xlv3_image);            return view;        }    }    class ViewHolder{        ImageView xlv3_image;        TextView xlv3_title;    }    class MyPagerAdaPter extends PagerAdapter{        @Override        public int getCount() {            return da.getTop_stories().size();        }        @Override        public boolean isViewFromObject(View view, Object object) {            return view == object;        }        @Override        public Object instantiateItem(ViewGroup container, int position) {            container.addView(viewList.get(position));            return viewList.get(position);        }        @Override        public void destroyItem(ViewGroup container, int position, Object object) {//            super.destroyItem(container, position, object);            container.removeView((View) object);        }    }}