protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); pager = findViewById(R.id.viewpager); group = findViewById(R.id.group); li = new ArrayList<>(); li.add(new Afragment()); li.add(new Bfragment()); li.add(new Cfragment()); li.add(new Dfragment()); pager.setAdapter(new FragmentPagerAdapter(getSupportFragmentManager()) {  @Override  public Fragment getItem(int position) {  return li.get(position);  }  @Override  public int getCount() {  return li.size();  } }); group.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {  @Override  public void onCheckedChanged(RadioGroup radioGroup, int i) {  switch (i){   case R.id.r1:   pager.setCurrentItem(0);   break;   case R.id.r2:   pager.setCurrentItem(1);   break;   case R.id.r3:   pager.setCurrentItem(2);   break;   case R.id.r4:   pager.setCurrentItem(3);   break;  }  } }); }

 <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".ui.MainActivity"> <LinearLayout android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <android.support.v4.view.ViewPager  android:id="@+id/viewpager"  android:layout_width="match_parent"  android:layout_height="0dp"  android:layout_weight="9"  >  </android.support.v4.view.ViewPager>  <RadioGroup  android:id="@+id/group"  android:layout_width="match_parent"  android:layout_height="wrap_content"  android:layout_weight="1"  android:orientation="horizontal"  >  <RadioButton  android:id="@+id/r1"  android:layout_width="wrap_content"  android:layout_height="match_parent"  android:button="@null"  android:gravity="center"  android:layout_weight="1"  android:text="Afrag"/>  <RadioButton  android:id="@+id/r2"  android:layout_width="wrap_content"  android:layout_height="match_parent"  android:button="@null"  android:gravity="center"  android:layout_weight="1"  android:text="Bfrag"/>  <RadioButton  android:id="@+id/r3"  android:layout_width="wrap_content"  android:layout_height="match_parent"  android:button="@null"  android:gravity="center"  android:layout_weight="1"  android:text="Cfrag"/>  <RadioButton  android:id="@+id/r4"  android:layout_width="wrap_content"  android:layout_height="match_parent"  android:button="@null"  android:gravity="center"  android:layout_weight="1"  android:text="Dfrag"/>  </RadioGroup>  </LinearLayout> </android.support.constraint.ConstraintLayout>

public class Afragment extends Fragment{ private int page=1; private XListView listView; private MyBaseAdapter adapter; ResponseBean responseBean;  @Nullable @Override public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {  View view = View.inflate(getActivity(), R.layout.afrag, null);   listView = view.findViewById(R.id.xlv);  adapter = new MyBaseAdapter(getLayoutInflater());  listView.setAdapter(adapter);   listView.setPullLoadEnable(true);  listView.setXListViewListener(new XListView.IXListViewListener() {  @Override  public void onRefresh() {   page=0;   loadData(page);  }   @Override  public void onLoadMore() {   loadData(page);   }  });  loadData(page);  return view; }  private String url =  "http://apis.juhe.cn/cook/query?key=3ec004200a6a2f4cf4774e480c006375&menu=%E8%A5%BF%E7%BA%A2%E6%9F%BF&rn=10&pn=";  private void loadData(int page){   String urlString=url+page;  new AsyncTask<String,Void,List<DataItem>>(){   @Override  protected List<DataItem> doInBackground(String... strings) {   try {   URL url = new URL(strings[0]);   HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();   urlConnection.setRequestMethod("GET");   urlConnection.setReadTimeout(5000);   urlConnection.setConnectTimeout(5000);   int responseCode = urlConnection.getResponseCode();   if (responseCode==200){    String result=String2(urlConnection.getInputStream());    responseBean = new Gson().fromJson(result, ResponseBean.class);   }else {    }   return responseBean == null ?null:responseBean.getResult().getData();   } catch (MalformedURLException e) {   e.printStackTrace();   } catch (IOException e) {   e.printStackTrace();   }   return null;  }   @Override  protected void onPostExecute(List<DataItem> dataItems) {   super.onPostExecute(dataItems);   if (dataItems == null) {   Toast.makeText(getActivity(), "請求數據錯誤", Toast.LENGTH_LONG).show();   return;   }   updateData(dataItems);   loadCompleted();   }  }.execute(urlString); }  private void updateData(List<DataItem> dataItems){  if (page==0){  adapter.setDatas(dataItems);  }else {  adapter.addDatas(dataItems);   }  }  private void loadCompleted(){  page++;  listView.stopRefresh();  listView.stopLoadMore(); }  private String String2(InputStream stream){  StringBuilder sb = new StringBuilder();  BufferedReader reader = new BufferedReader(new InputStreamReader(stream));  try {  for (String tmp=reader.readLine();tmp!=null;tmp=reader.readLine()){   sb.append(tmp);  }  } catch (IOException e) {  e.printStackTrace();  }  return sb.toString(); } }

public class MyBaseAdapter extends BaseAdapter{ private List<DataItem> datas; private LayoutInflater layoutInflater; public MyBaseAdapter(LayoutInflater layoutInflater) { this.layoutInflater = layoutInflater; datas=new ArrayList<>(); } public void setDatas(List<DataItem> datas) { datas.clear(); if (datas!=null){  datas.addAll(datas); } notifyDataSetChanged(); } public void addDatas(List<DataItem> dataItems) { if (dataItems!=null){  datas.addAll(dataItems);  notifyDataSetChanged(); } } public final int VIEW_TYPE_COUNT=2; public final int IMAGE_TEXT_TYPE=0; public final int TEXT_TYPE=1; @Override public int getItemViewType(int position) { if (position % 2==0){  return IMAGE_TEXT_TYPE; }else {  return TEXT_TYPE; } } @Override public int getViewTypeCount() { return VIEW_TYPE_COUNT; } @Override public int getCount() { return datas.size(); } @Override public Object getItem(int i) { return datas.get(i); } @Override public long getItemId(int i) { return i; } @Override public View getView(int i, View view, ViewGroup viewGroup) { if (getItemViewType(i)==IMAGE_TEXT_TYPE){  ViewHolder viewHolder=null;  if (view==null){  view = layoutInflater.inflate(R.layout.item, viewGroup,false);  viewHolder = new ViewHolder(view);  }else {  viewHolder = (ViewHolder) view.getTag();  }  viewHolder.bindData((DataItem) getItem(i)); }else {  ViewHolder2 viewHolder2;  if (view==null){  view = layoutInflater.inflate(R.layout.item_text, viewGroup, false);  viewHolder2 = new ViewHolder2();  viewHolder2.textView = view.findViewById(R.id.text);  view.setTag(viewHolder2);  }else {  viewHolder2 = (ViewHolder2) view.getTag();  }  viewHolder2.textView.setText(datas.get(i).getTitle()); } return view; } public class ViewHolder{ private ImageView icon; private TextView title; private TextView date; public ViewHolder(View view) {  icon = view.findViewById(R.id.icon);  date = view.findViewById(R.id.date);  view.setTag(this); } public void bindData(DataItem item) {  title.setText(item.getTitle());  date.setText(item.getId());  ImageLoader.getInstance().displayImage(item.getFirst(),icon   , ImageloaderConfigs.getDefult(icon.getContext())); } } public class ViewHolder2{ TextView textView; }}

public class ImageloaderConfigs { public static ImageLoaderConfiguration getImageLoader(Context context){ ImageLoaderConfiguration configuration = new ImageLoaderConfiguration.Builder(context)  .memoryCacheSizePercentage(13)  .diskCacheSize(50*1024*1024)  .defaultDisplayImageOptions(DisplayImageOptions.createSimple())  .writeDebugLogs()  .build(); return configuration; } public static DisplayImageOptions getDefult(Context context){ DisplayImageOptions imageOptions = new DisplayImageOptions.Builder()  .cacheInMemory(true)  .cacheOnDisk(true)  .bitmapConfig(Bitmap.Config.RGB_565)  .imageScaleType(ImageScaleType.EXACTLY_STRETCHED)  .displayer(new CircleBitmapDisplayer())  .build(); return imageOptions; }}

public class App extends Application{ @Override public void onCreate() { super.onCreate(); ImageLoader.getInstance().init(ImageloaderConfigs.getImageLoader(this)); }}

public class ResponseBean { private int resultcode; private String reason; private Result result; public int getResultcode() { return resultcode; } public String getReason() { return reason; } public Result getResult() { return result; } public class Result{ private List<DataItem> data; public List<DataItem> getData() {  return data; } }}

public class DataItem { private String id; private String title; private List<String> albums; public String getId() { return id; } public String getTitle() { return title; } public List<String> getAlbums() { return albums; } public String getFirst(){ return albums==null || albums.size()==0? "" : albums.get(0); }