问题
My SearchFragment is the host Fragment for two other Fragments: SearchUsersFragment and SearchEventsFragment. The way I have it organized is the TabLayout and Viewpager are in the SearchFragment, and the RecyclerView, Adapters, and ArrayList are in the two child Fragments.
What I would like to do is implement a SearchBar (EditText), which I have already done in the SearchFragment and use that SearchBar to filter through the users (in SearchUsersFragment) and events (in SearchEventsFragment).
The problem: is I have written two methods in each child Fragment searchusers(); and readUsers();. The method searchUsers(); I made public so that I can add it to the SearchFragment in onTextChangedListener, but still the users whose names begin with the letters that I type into the SearchBar aren't coming up.
Can someone please tell me how to fix this? I have been working on this for 3 days and can't get the users or events to come up that start with the letters someone types in the SearchBar.
SearchFragment
public class SearchFragment extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_search, container, false);
final TabLayout tabLayout = v.findViewById(R.id.tab_layout);
final ViewPager viewPager = v.findViewById(R.id.viewpager);
tabLayout.addTab(tabLayout.newTab().setIcon(R.drawable.icon_people_black));
tabLayout.addTab(tabLayout.newTab().setIcon(R.drawable.icon_event_available_black));
ViewPagerAdapter viewPagerAdapter = new ViewPagerAdapter(getChildFragmentManager());
viewPagerAdapter.addFragment(new SearchUsersFragment(), "");
viewPagerAdapter.addFragment(new SearchEventsFragment(), "");
viewPager.setAdapter(viewPagerAdapter);
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
tabLayout.addOnTabSelectedListener(new TabLayout.ViewPagerOnTabSelectedListener(viewPager));
EditText searchBar = v.findViewById(R.id.search_bar);
searchBar.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
FragmentManager fragmentManager = getChildFragmentManager();
SearchUsersFragment searchUsersFragment = (SearchUsersFragment) fragmentManager.findFragmentById(R.id.fragment_search_users);
if (searchUsersFragment != null) {
searchUsersFragment.searchUsers(s.toString().toLowerCase());
}
}
@Override
public void afterTextChanged(Editable s) {
}
});
return v;
}
static class ViewPagerAdapter extends FragmentPagerAdapter {
private ArrayList<Fragment> mFragments;
private ArrayList<String> mTitles;
ViewPagerAdapter(@NonNull FragmentManager fm) {
super(fm);
this.mFragments = new ArrayList<>();
this.mTitles = new ArrayList<>();
}
@NonNull
@Override
public Fragment getItem(int position) {
return mFragments.get(position);
}
@Override
public int getCount() {
return mFragments.size();
}
void addFragment(Fragment fragment, String title) {
mFragments.add(fragment);
mTitles.add(title);
}
@Nullable
@Override
public CharSequence getPageTitle(int position) {
return mTitles.get(position);
}
}
}
SearchUsersFragment
public class SearchUsersFragment extends Fragment {
RecyclerView mRecyclerView;
UserAdapter mUserAdapter;
List<User> mUserList;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_search_users, container, false);
mRecyclerView = view.findViewById(R.id.recycler_view);
mRecyclerView.setHasFixedSize(true);
mRecyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
mUserList = new ArrayList<>();
mUserAdapter = new UserAdapter(getContext(), mUserList, true);
mRecyclerView.setAdapter(mUserAdapter);
readUsers();
return view;
}
public void searchUsers(String s) {
Query query = FirebaseDatabase.getInstance().getReference("Users").orderByChild("username").startAt(s).endAt(s + "\uf8ff");
query.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
mUserList.clear();
for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
User user = snapshot.getValue(User.class);
if (user != null) {
mUserList.add(user);
}
}
mUserAdapter.notifyDataSetChanged();
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
}
private void readUsers() {
final FirebaseUser firebaseUser = FirebaseAuth.getInstance().getCurrentUser();
DatabaseReference reference = FirebaseDatabase.getInstance().getReference("Users");
reference.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
mUserList.clear();
for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
User user = snapshot.getValue(User.class);
if (firebaseUser != null && user != null && !user.getId().equals(firebaseUser.getUid())) {
mUserList.add(user);
}
}
mUserAdapter.notifyDataSetChanged();
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
}
}
SearchEventsFragment
public class SearchEventsFragment extends Fragment {
RecyclerView mRecyclerView;
SearchEventsAdapter mSearchEventsAdapter;
List<Post> mPostList;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_search_events, container, false);
mRecyclerView = view.findViewById(R.id.recycler_view);
mRecyclerView.setHasFixedSize(true);
mRecyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
mPostList = new ArrayList<>();
mSearchEventsAdapter = new SearchEventsAdapter(getContext(), mPostList);
mRecyclerView.setAdapter(mSearchEventsAdapter);
readEvents();
return view;
}
private void readEvents() {
DatabaseReference reference = FirebaseDatabase.getInstance().getReference("Posts");
reference.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
mPostList.clear();
for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
Post post = snapshot.getValue(Post.class);
if (post != null) {
mPostList.add(post);
}
}
mSearchEventsAdapter.notifyDataSetChanged();
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
}
}
回答1:
I have used a searchView here for filtering 3 fragments together
searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
@Override
public boolean onQueryTextSubmit(String query) {
return false;
}
@Override
public boolean onQueryTextChange(String newText) {
mAdapter.getFilter().filter(newText);
fAdapter.getFilter().filter(newText);
rAdapter.getFilter().filter(newText);
return false;
}
});
And then in my adapters I have done implements Filterable and
@Override
public Filter getFilter() {
return myFilter;
}
private Filter myFilter = new Filter() {
@Override
protected FilterResults performFiltering(CharSequence constraint) {
ArrayList<String> filterList = new ArrayList<>();
if (constraint == null || constraint.length() == 0) {
filterList.addAll(MainActivity.Db.getWholeData());
} else {
String toFilter = constraint.toString().toLowerCase().trim();
for (String item : MainActivity.Db.getWholeData()) {
if (item.toLowerCase().contains(toFilter)) {
filterList.add(item);
}
}
}
clickPurposeFav = filterList;
FilterResults filterResults = new FilterResults();
filterResults.values = filterList;
return filterResults;
}
@Override
protected void publishResults(CharSequence constraint, FilterResults results) {
MainActivity.arrList.clear();
MainActivity.arrList.addAll((List) results.values);
}
};
来源：https://stackoverflow.com/questions/62236037/searchbar-with-tablayout-and-viewpager-searchbar-edittext-doesnt-filter-thro