i use this tutorial for creating tab. and now i have a recyclerview in each fragment and i want to notify them from mainactivity. how to access the adapter in fragment?
i use this for calling refreshData() method in fragment:
TabFragment1 tabFragment = (TabFragment1) getSupportFragmentManager().findFragmentByTag(TabFragment1.class.getSimpleName());
if (tabFragment != null) {
tabFragment.refreshData();
}
but that return null.
mainActivity:
TabLayout tabLayout = (TabLayout) findViewById(R.id.tabLayout);
tabLayout.addTab(tabLayout.newTab().setText("Tab1"));
tabLayout.addTab(tabLayout.newTab().setText("Tab2"));
final PagerAdapter adapter = new PagerAdapter
(getSupportFragmentManager(), tabLayout.getTabCount());
viewPager.setAdapter(adapter);
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
@Override
public void onTabSelected(TabLayout.Tab tab) {
viewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(TabLayout.Tab tab) {
}
@Override
public void onTabReselected(TabLayout.Tab tab) {
}
});
PagerAdapter:
public class PagerAdapter extends FragmentStatePagerAdapter {
int mNumOfTabs;
public PagerAdapter(FragmentManager fm, int NumOfTabs) {
super(fm);
this.mNumOfTabs = NumOfTabs;
}
@Override
public Fragment getItem(int position) {
switch (position) {
case 0:
TabFragment1 tab1 = new TabFragment1();
return tab1;
case 1:
TabFragment2 tab2 = new TabFragment2();
return tab2;
case 2:
TabFragment3 tab3 = new TabFragment3();
return tab3;
case 3:
TabFragment4 tab4 = new TabFragment4();
return tab4;
default:
return null;
}
}
@Override
public int getCount() {
return mNumOfTabs;
}
}
One of myTabFragment:
public CardAdapter adapter;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
RecyclerView v = (RecyclerView) inflater.inflate(R.layout.tab_fragment_1, container, false);
SetupRecycleView(v);
return v;
}
public void refreshData() {
adapter.notifyDataSetChanged();
}
void SetupRecycleView(RecyclerView recList) {
recList.setHasFixedSize(true);
LinearLayoutManager llm = new LinearLayoutManager(G.context);
llm.setOrientation(LinearLayoutManager.VERTICAL);
//recList.setLayoutManager(new GridLayoutManager(G.context, 2));
recList.setLayoutManager(llm);
List<StructGhaza> ghazas = StructGhaza.getAllGhaza("2");
adapter = new CardAdapter(ghazas);
recList.setAdapter(adapter);
}
The CardAdapter:
public class CardAdapter extends RecyclerView.Adapter<CardAdapter.GhazaViewHolder> {
private List<StructGhaza> ghazas;
public CardAdapter(List<StructGhaza> ghazaList) {
this.ghazas = ghazaList;
}
@Override
public int getItemCount() {
return ghazas.size();
}
@Override
public void onBindViewHolder(GhazaViewHolder ghazaViewHolder, int position) {
StructGhaza ghaza = ghazas.get(position);
ghazaViewHolder.vTitle.setText(ghaza.Name);
//----Load Image
Glide.with(G.context)
.load(ghaza.Aks)
.placeholder(R.drawable.loading_spinner)
.crossFade()
.into(ghazaViewHolder.itemImg);
//---------------
ghazaViewHolder.Rate.setRating(ghaza.Star);
ghazaViewHolder.sampleLayout.setHoverView(ghazaViewHolder.hover);
ghazaViewHolder.sampleLayout.addChildAppearAnimator(ghazaViewHolder.hover, R.id.tvHover, Techniques.FlipInX);
ghazaViewHolder.sampleLayout.addChildDisappearAnimator(ghazaViewHolder.hover, R.id.tvHover, Techniques.FlipOutX);
}
@Override
public GhazaViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
View itemView = LayoutInflater.
from(viewGroup.getContext()).
inflate(R.layout.fragment_carditem, viewGroup, false);
return new GhazaViewHolder(itemView);
}
public static class GhazaViewHolder extends RecyclerView.ViewHolder {
protected TextView vTitle;
protected BlurLayout sampleLayout;
protected View hover;
protected ImageView itemImg;
protected RatingBar Rate;
public GhazaViewHolder(View v) {
super(v);
sampleLayout = (BlurLayout) v.findViewById(R.id.sample);
itemImg = (ImageView) v.findViewById(R.id.item_img);
hover = LayoutInflater.from(G.context).inflate(R.layout.fragment_hover, null);
vTitle = (TextView) v.findViewById(R.id.titleTv);
Rate = (RatingBar) v.findViewById(R.id.rating);
}
}
}
EDIT: After many test, the previous answer work with Android < 21, but for Android > 21 it's little bit weird, it doesn't seems to work in the same way.
Finally, I solved it like that, and it works everywhere:
In your adapter:
HashMap<Integer, Fragment> mPageReferenceMap = new HashMap<>();
@Override
public Object instantiateItem(ViewGroup container, int position) {
Fragment fragment = (Fragment) super.instantiateItem(container, position);
mPageReferenceMap.put(position, fragment);
return fragment;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
super.destroyItem(container, position, object);
mPageReferenceMap.remove(position);
}
public Fragment getFragment(int key) {
return mPageReferenceMap.get(key);
}
And you call getFragment where you want in your activity like that:
int index = viewPager.getCurrentItem();
ViewPagerAdapter adapter = ((ViewPagerAdapter)viewPager.getAdapter());
final YourFragment tabFragment = (YourFragment) adapter.getFragment(index);
PREVIOUS ANSWER :
Warning : it doesn't really work with Android > 21
I had the same problem. Finally, i did'nt use id or tag.
Instead of using:
CustomFragment customFragment = (CustomFragment) getSupportFragmentManager().findFragmentByTag(getString(R.string.fragment_custo_tag));
use this:
CustomFragment customFragment = (CustomFragment) getSupportFragmentManager().getFragments().get(0);
to get instance of CustomFragment.
I have put get(0) as your position of CustomFragment instance is at zero.
I found this issue here: Set and get using tag a fragment in android
This is late but I hope this will be helpful for someone. To find fragment by tag we can do this:
String tag=getSupportFragmentManager().getFragments().get(index).getTag();
SecondFragment f = (SecondFragment) getSupportFragmentManager().findFragmentByTag(tag);
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