安卓标签视图片段回收器视图搜索过滤器

Question

我想在选项卡视图中实现搜索过滤器 使用来自sqlite数据库的数据片段，经过三天多的经历，尽管这个和这个没有成功，最后我遇到了这个，这似乎是干净的想法，因为我对Android开发很陌生。 我试图实现它，但似乎不起作用，这意味着搜索菜单项不会膨胀，我也没有得到任何结果，我不知道我在哪里弄错了，根本没有错误，任何关于什么是问题以及如何让它工作的想法。

这是片段代码

public class TabFragment3 extends Fragment implements SearchView.OnQueryTextListener {
private RecyclerView recyclerView;
private LinearLayoutManager layoutManager;
private UsersAdapter adapter;
ArrayList<HashMap<String, String>>  arrayList;
DBController controller = new DBController(getContext());
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view =inflater.inflate(R.layout.tab_fragment_3, container, false);
    recyclerView = (RecyclerView) view.findViewById(R.id.usersList);
    recyclerView.setHasFixedSize(true);
    layoutManager = new LinearLayoutManager(getContext());
    recyclerView.setLayoutManager(layoutManager);
    controller = new DBController(getContext());
    arrayList = controller.getAllUsers();
    adapter = new UsersAdapter(arrayList,getContext());
    recyclerView.setAdapter(adapter);
    adapter.notifyDataSetChanged();
    return view;
      }
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
    inflater.inflate(R.menu.menu_main, menu);
    final MenuItem item = menu.findItem(R.id.action_search);
    final SearchView searchView = (SearchView) MenuItemCompat.getActionView(item);
    searchView.setOnQueryTextListener(this);
    MenuItemCompat.setOnActionExpandListener(item,new MenuItemCompat.OnActionExpandListener() {
        @Override
        public boolean onMenuItemActionCollapse(MenuItem item) {
             arrayList = controller.getAllUsers();
           // Do something when collapsed
            adapter.setFilter(arrayList);
            return true; // Return true to collapse action view
        }
        @Override
        public boolean onMenuItemActionExpand(MenuItem item) {
           // Do something when expanded
            return true; // Return true to expand action view
        }
    });
}
@Override
public boolean onQueryTextChange(String query) {
    return false;
}
@Override
public boolean onQueryTextSubmit(String newText) {
 // Here is where we are going to implement the filter logic
    newText = newText.toLowerCase();
    ArrayList<HashMap<String, String>> userlist = controller.getAllUsers();
    ArrayList<HashMap<String, String>> newList= new ArrayList<>();
    for(HashMap<String, String> entry : userlist){
        String name2= entry.get("number").toLowerCase();
        if(name2.contains(newText)){
            newList.add(entry);
        }}
    adapter.setFilter(newList);
    return true;
}

}

 ///  adapter class
 public class UsersAdapter extends RecyclerView.Adapter<UsersAdapter.UserViewHolder> {
ArrayList<HashMap<String, String>> mDataSet= new ArrayList<HashMap<String, String>> ();
Context ctx;
public UsersAdapter(ArrayList<HashMap<String, String>> mDataSet,Context ctx) {
    this.mDataSet = mDataSet;
    this.ctx=ctx;
}
@Override
public UserViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.user_row, parent, false);
    UserViewHolder userViewHolder = new UserViewHolder(v,mDataSet,ctx);
    return userViewHolder;
}
@Override
public void onBindViewHolder(UserViewHolder holder, int position) {
    holder.name_entry.setText(mDataSet.get(position).get("userId"));
    holder.email_entry.setText(mDataSet.get(position).get("userName"));
    holder.icon_entry.setText(""+mDataSet.get(position).get("number"));
}
@Override
public int getItemCount() {
    return mDataSet.size();
}
public static class UserViewHolder extends RecyclerView.ViewHolder  {
    CardView cardView;
    TextView name_entry, email_entry, icon_entry;
    Context ctx;
    ArrayList<HashMap<String, String>> mDataSet= new ArrayList<HashMap<String, String>> ();
    public UserViewHolder(View itemView, ArrayList<HashMap<String, String>> mDataSet,Context ctx) {
        super(itemView);
        this.mDataSet=mDataSet;
        this.ctx= ctx;
        cardView = (CardView) itemView.findViewById(R.id.user_layout);
        name_entry = (TextView) itemView.findViewById(R.id.name_entry);
        email_entry = (TextView) itemView.findViewById(R.id.email_entry);
        icon_entry = (TextView) itemView.findViewById(R.id.icon_entry);
    }
}
@Override
public void onAttachedToRecyclerView(RecyclerView recyclerView) {
    super.onAttachedToRecyclerView(recyclerView);
}
public void setFilter(ArrayList<HashMap<String, String>> newList){
    mDataSet= new ArrayList<HashMap<String, String>>();
    mDataSet.addAll(newList);
    notifyDataSetChanged();
}

}

///主要

public class MainActivity extends AppCompatActivity  implements TabLayout.OnTabSelectedListener,SearchView.OnQueryTextListener  {
private ViewPager viewPager;
PagerAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
    tabLayout.addTab(tabLayout.newTab().setText("Tab 1"));
    tabLayout.addTab(tabLayout.newTab().setText("Tab 2"));
    tabLayout.addTab(tabLayout.newTab().setText("Tab 3"));
    tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
    final ViewPager viewPager = (ViewPager) findViewById(R.id.pager);
    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) {
        }
    });
}
@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) {
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
    int id = item.getItemId();
    return super.onOptionsItemSelected(item);
}
public boolean onQueryTextSubmit(String query)
{ return false;
 }
@Override
public boolean onQueryTextChange(String newText) {
  return false;
        }

}

Answer 1

1. 在 TabFragment3 的onCreateView()方法中添加setHasOptionsMenu(true)。 它告诉主机活动您的片段具有要添加的菜单选项。

2. 还要添加super.onCreateOptionsMenu(menu,inflater)..

   @Override public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { inflater.inflate(R.menu.menu_main, menu); super.onCreateOptionsMenu(menu,inflater); }

3. 在 MainActivity 的onOptionsItemSelected(MenuItem item)中返回 false，因为菜单项操作将在 TabFragment3 的onOptionsItemSelected(MenuItem item)中被占用。