对多个 TabLayout 仅使用一个带有 RecyclerView 的 Fragment，无法在选项卡更改时正确更新数据

Posted 2023-04-18

【中文标题】对多个 TabLayout 仅使用一个带有 RecyclerView 的 Fragment，无法在选项卡更改时正确更新数据

【英文标题】：Using only one Fragment with RecyclerView for multiple TabLayout , not updating data correctly on tabs change

【发布时间】：2019-03-19 20:48:47

【问题描述】：

有一个与我类似的问题，但该解决方案不适用于我的情况。 我提到的问题是 this 我有一个名为“HomeFragment”的片段，它由一个 VieWPager 和 TabLayout 组成。我正在从后端动态添加选项卡。所以我为所有选项卡使用另一个名为“SecondFragment”的片段，因为所有选项卡都只包含一个 RecyclerView。我正在填充 SecondFragment 的 RecyclerView onCreate()。我的问题出现在这里，当我滑动或更改选项卡时，RecyclerView 没有正确更新。继续滑动时，数据会发生变化，但与所选选项卡不对应。我已经记录了流程，并且在刷卡时从后端获取了正确的数据，但它没有更新 RrecyclerView。

我的 HomeFragment 类是

public class HomeFragment extends Fragment implements HTTPCallback 

private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
private OnFragmentInteractionListener mListener;
private RecyclerView recyclerView;
private CardView cardview;
private boolean isShow;
View rootview;
private Toolbar toolbar;
private ImageView imageView, tabBg;
private CollapsingToolbarLayout collapsingToolbar;
private TabLayout mTabLayout;
Context context;
private ViewPager mViewPager, mViewPager1;
AppBarLayout appBarLayout;
Integer url_size;
int i;
boolean stopSliding = false;
String url, url2;
String message, version;
private ArrayList<HomeModel> planList;
JSONObject jsonObject, jsonObject2;
JSONArray jsonArray, jsonArray2;
ViewPagerAdapter adapter;

List<Product> products;
int numTab = 0;
private SharedPreferences sharedPreferences;
private SharedPreferences.Editor editor;

public HomeFragment() 


public static HomeFragment newInstance(String param1, String param2) 
    HomeFragment fragment = new HomeFragment();
    Bundle args = new Bundle();
    args.putString(ARG_PARAM1, param1);
    args.putString(ARG_PARAM2, param2);
    fragment.setArguments(args);
    return fragment;


@Override
public void onCreate(Bundle savedInstanceState) 
    super.onCreate(savedInstanceState);
    if (getArguments() != null) 

    


@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) 
    rootview = inflater.inflate(R.layout.fragment_home, container, false);
    appBarLayout = (AppBarLayout) rootview.findViewById(R.id.appbar);
    mViewPager1 = (ViewPager) rootview.findViewById(R.id.view_pager);
    collapsingToolbar = (CollapsingToolbarLayout) rootview.findViewById(R.id.collapsing_toolbar);
    sharedPreferences = getContext().getSharedPreferences("spade", Context.MODE_PRIVATE);
    editor = sharedPreferences.edit();

    mViewPager = (ViewPager) rootview.findViewById(R.id.viewpager);
    mTabLayout = (TabLayout) rootview.findViewById(R.id.tabs);

    mTabLayout.setSelectedTabIndicatorColor(Color.parseColor("#FF0000"));
    mTabLayout.setSelectedTabIndicatorHeight((int) (5 * getResources().getDisplayMetrics().density));
    mTabLayout.setTabTextColors(Color.parseColor("#727272"), Color.parseColor("#FF0000"));

    new HTTPRequest(getContext(), null, null, HTTPRequest.METHOD.GET, this).execute(url2);

    mViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() 
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) 

        

        @Override
        public void onPageSelected(int position) 
            if (position == 0) 
                appBarLayout.setExpanded(true);

             else 
                appBarLayout.setExpanded(false);
            
        

        @Override
        public void onPageScrollStateChanged(int state) 

        
    );

    try 

     catch (Exception e) 
        e.printStackTrace();
    

    mTabLayout.setOnTabSelectedListener(
            new TabLayout.ViewPagerOnTabSelectedListener(mViewPager) 
                @Override
                public void onTabSelected(TabLayout.Tab tab) 
                    super.onTabSelected(tab);

                    mViewPager.setCurrentItem(tab.getPosition());
                    numTab = tab.getPosition();
                    HomeModel browsePlan = planList.get(numTab);
                    editor.putString("tab", browsePlan.getName()).commit();
                
            );

    return rootview;


public void onButtonPressed(Uri uri) 
    if (mListener != null) 
        mListener.onFragmentInteraction(uri);
    


@Override
public void onConnectionStarted() 


@Override
public void onConnectionFailed() 


@Override
public void onCompleted(JSONObject resultData) 

    HomeModel model;
    planList = new ArrayList<>();
    adapter = new ViewPagerAdapter(getChildFragmentManager());
    try 
        jsonArray = resultData.getJSONArray("details");
        editor.putString("tab", jsonArray.getJSONObject(0).getString("name"));
        editor.commit();
        for (int i = 0; i < jsonArray.length(); i++) 

            jsonObject2 = jsonArray.getJSONObject(i);
            model = new HomeModel();
            model.setCatid(jsonObject2.getString("id"));
            model.setImage(jsonObject2.getString("image"));
            model.setName(jsonObject2.getString("name"));
            planList.add(model);
            setupViewPager(mViewPager, jsonObject2.getString("name"));

        
        setAdapter();
     catch (JSONException e) 
        e.printStackTrace();
    



private void setAdapter() 

    appBarLayout.setExpanded(false);
    mViewPager.setAdapter(adapter);
    mTabLayout.setupWithViewPager(mViewPager);


public interface OnFragmentInteractionListener 
    // TODO: Update argument type and name
    void onFragmentInteraction(Uri uri);


private void setupViewPager(ViewPager mViewPager, String name) 
    adapter.addFragment(new SecondFragment(), name);
    mViewPager.setOffscreenPageLimit(1);


@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) 
    super.onActivityResult(requestCode, resultCode, data);



class ViewPagerAdapter extends FragmentPagerAdapter 
    private final List<Fragment> mFragmentList = new ArrayList<>();
    private final List<String> mFragmentTitleList = new ArrayList<>();

    public ViewPagerAdapter(FragmentManager manager) 
        super(manager);
    

    @Override
    public Fragment getItem(int position) 
        return mFragmentList.get(position);
    

    @Override
    public int getCount() 
        return mFragmentList.size();
    

    public void addFragment(Fragment fragment, String title) 
        mFragmentList.add(fragment);
        mFragmentTitleList.add(title);
    

    @Override
    public CharSequence getPageTitle(int position) 
        return mFragmentTitleList.get(position);
    

SecondFragment 类是

public class SecondFragment extends Fragment implements HTTPCallback 

private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
String mParam1;
String mParam2;
Button solo, grp;
View rootview;
Fragment fragment;
String url;
JSONObject jsonObject, jsonObject2;
JSONArray jsonArray, jsonArray2;
private ArrayList<Spaceship> planList;
RecyclerView rv;
private RecyclerHomeAdapter adapter = new RecyclerHomeAdapter(getContext(), planList);
;
private SharedPreferences sharedPreferences;
String tab_name;

private OnFragmentInteractionListener mListener;

public SecondFragment() 


public static SecondFragment newInstance(String s, String s1) 
    SecondFragment fragment = new SecondFragment();
    Bundle args = new Bundle();
    return fragment;


@Override
public void onCreate(Bundle savedInstanceState) 
    super.onCreate(savedInstanceState);
    if (getArguments() != null) 
        mParam1 = getArguments().getString(ARG_PARAM1);
        mParam2 = getArguments().getString(ARG_PARAM2);
    


@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) 
    rootview = inflater.inflate(R.layout.fragment_second, container, false);
    sharedPreferences = getContext().getSharedPreferences("spade", Context.MODE_PRIVATE);

    tab_name = sharedPreferences.getString("tab", "onnumilla");
    rv = (RecyclerView) rootview.findViewById(R.id.rv);
    rv.setLayoutManager(new LinearLayoutManager(getContext()));
    url = "My_url_here";

    HashMap<String, String> data = new HashMap<String, String>();

    data.put("name", tab_name);

    new HTTPRequest2(getContext(), data, null, HTTPRequest2.METHOD.POST, this).execute(url);


    return rootview;


@Override
public void setUserVisibleHint(boolean isVisibleToUser) 
    super.setUserVisibleHint(isVisibleToUser);
    if (isVisibleToUser) 

        adapter.notifyDataSetChanged();

// getFragmentManager().beginTransaction().detach(this).attach(this).commit();

public void onButtonPressed(Uri uri) 
    if (mListener != null) 
        mListener.onFragmentInteraction(uri);
    


@Override
public void onConnectionStarted() 


@Override
public void onConnectionFailed() 


@Override
public void onCompleted(JSONObject resultData) 

    Spaceship model;
    planList = new ArrayList<>();
    planList.clear();
    try 
        jsonArray = resultData.getJSONArray("products");
        for (int i = 0; i < jsonArray.length(); i++) 

            jsonObject2 = jsonArray.getJSONObject(i);
            model = new Spaceship();
            model.setName(jsonObject2.getString("package_name"));
            model.setImage(jsonObject2.getString("images"));
            planList.add(model);
        

        setAdapter();
     catch (JSONException e) 
        e.printStackTrace();
    


private void setAdapter() 
    adapter = new RecyclerHomeAdapter(getContext(), planList);
    adapter.notifyDataSetChanged();
    rv.setAdapter(adapter);
    adapter.notifyDataSetChanged();


public interface OnFragmentInteractionListener 
    // TODO: Update argument type and name
    void onFragmentInteraction(Uri uri);

这对我不起作用。但是在我添加 getFragmentManager().beginTransaction().detach(this).attach(this).commit(); 时的 setUserVisibleHint(boolean isVisibleToUser) 方法中 而不是adapter.notifyDataSetChanged(); 它可以工作，但是在滑动选项卡上隐藏以前的数据需要一些时间。

任何人，请给我一个解决方案。我提出了很多问题，但对我没有任何作用。感谢您的所有回复。

【问题讨论】：

请同时发布您的活动代码。

@Manish 我在片段 HomeFragment 中使用标签。这是问题中的第一个代码。与活动无关。在 HomeFragment 中有 TabLayout 和 ViewPager 和 SecondFragment 添加到该 ViewPager

你找到解决办法了吗？？

@Hamza 还没有，抱歉回复晚了

【参考方案1】：

这似乎是 ViewPager 页面兑现问题。请从 onCreateView() 调用以下代码 的 HomeFragment。

mViewPager.setOffscreenPageLimit(1);

【讨论】：

我必须在问题中描述的 SetUserVisibleHint 方法中添加“getFragmentManager().beginTransaction().detach(this).attach(this).commit();。没有这条线它不起作用即使在设置 mViewPager.setOffscreenPageLimit(1);