问题
There is a question similar to me, but that solution didn't work for my case. The question I have referred is this I have a fragment named "HomeFragment" which consists of a VieWPager and TabLayout. I am adding tabs dynamically from the backend. So I am using another Fragment named "SecondFragment" for all tabs since all tabs contain a RecyclerView only. I am populating the RecyclerView onCreate() of the SecondFragment. My issue comes here that when I swipe or change the tab, the RecyclerView not updating correctly. On continuing swiping, the data changes but it does not correspond to the selected tab. I have logged the flow and I am getting correct data from backend on swiping, but it does not updating the RrecyclerView.
My HomeFragment class is
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 class is
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);
}
}
This doesn't work for me. But in the setUserVisibleHint(boolean isVisibleToUser) method when i add getFragmentManager().beginTransaction().detach(this).attach(this).commit();
instead of adapter.notifyDataSetChanged();
it works but it takes some time to hide previous data on swiping tab.
Anyone, please suggest me a solution. I have referred many questions but nothing works for me. All your response is appreciated.
回答1:
This seems to be ViewPager page cashing issue. pls call below code from onCreateView() of HomeFragment.
mViewPager.setOffscreenPageLimit(1);
来源:https://stackoverflow.com/questions/52816494/using-only-one-fragment-with-recyclerview-for-multiple-tablayout-not-updating