Question

我正在尝试在SearchView中实施ActionBar。我在适配器中使用notifyDataSetChanged()但Fragment没有更新。我正在使用调试器，似乎流程正常，但只有Fragment没有再次运行。这是我的代码：

这是我的Adapter类：

public class DessertAdapter extends RecyclerView.Adapter<DessertAdapter.DessertVh> {


private List<Dessert> desserts = new ArrayList<>();
OnItemClickListener clickListener;
private Context context;

public DessertAdapter(Context context) {
    this.context = context;

    desserts = Dessert.prepareDesserts(
            context.getResources().getStringArray(R.array.dessert_names),
            context.getResources().getStringArray(R.array.dessert_descriptions));
}

public void setFilter(ArrayList<Dessert> newList){
    desserts = new ArrayList<>();
    desserts.addAll(newList);
    notifyDataSetChanged();
}

@Override
public DessertVh onCreateViewHolder(ViewGroup parent, int viewType) {
    LayoutInflater inflater = LayoutInflater.from(parent.getContext());
    View view = inflater.inflate(R.layout.item_dessert, parent, false);
    return new DessertAdapter.DessertVh(view);
}

@Override
public void onBindViewHolder(DessertVh holder, int position) {
    Dessert dessert = desserts.get(position);

    holder.mName.setText(dessert.getName());
    holder.mDescription.setText(dessert.getDescription());
    holder.mFirstLetter.setText(String.valueOf(dessert.getFirstLetter()));

}

@Override
public int getItemCount() {
    return desserts == null ? 0 : desserts.size();
}

public class DessertVh extends RecyclerView.ViewHolder implements View.OnClickListener{

    private TextView mName;
    private TextView mDescription;
    private TextView mFirstLetter;

    public DessertVh(View itemView) {
        super(itemView);

        mName = (TextView) itemView.findViewById(R.id.txt_name);
        mDescription = (TextView) itemView.findViewById(R.id.txt_desc);
        mFirstLetter = (TextView) itemView.findViewById(R.id.txt_firstletter);

        itemView.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        clickListener.onItemClick(v, getPosition());
    }
}

public interface OnItemClickListener {
    public void onItemClick(View view, int position);
}

public void SetOnItemClickListener(final OnItemClickListener itemClickListener) {
    this.clickListener = itemClickListener;
}
}

这是我的Activity类，它也包含Fragment和FragmentPagerAdapter：

public class TabsHeaderActivity extends AppCompatActivity implements SearchView.OnQueryTextListener{
private static final String TAG = TabsHeaderActivity.class.getSimpleName();

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_tabs_header);

    final Toolbar toolbar = (Toolbar) findViewById(R.id.htab_toolbar);
    setSupportActionBar(toolbar);
    if (getSupportActionBar() != null) getSupportActionBar().setTitle("TECHNOLOGY");
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);

    final ViewPager viewPager = (ViewPager) findViewById(R.id.htab_viewpager);
    setupViewPager(viewPager);


    TabLayout tabLayout = (TabLayout) findViewById(R.id.htab_tabs);
    tabLayout.setupWithViewPager(viewPager);

    final CollapsingToolbarLayout collapsingToolbarLayout = (CollapsingToolbarLayout) findViewById(R.id.htab_collapse_toolbar);

    try {
        Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.edtech);
        Palette.from(bitmap).generate(new Palette.PaletteAsyncListener() {
            @SuppressWarnings("ResourceType")
            @Override
            public void onGenerated(Palette palette) {

                int vibrantColor = palette.getVibrantColor(R.color.primary_500);
                int vibrantDarkColor = palette.getDarkVibrantColor(R.color.primary_700);
                collapsingToolbarLayout.setContentScrimColor(vibrantColor);
                collapsingToolbarLayout.setStatusBarScrimColor(vibrantDarkColor);
            }
        });

    } catch (Exception e) {
        // if Bitmap fetch fails, fallback to primary colors
        Log.e(TAG, "onCreate: failed to create bitmap from background", e.fillInStackTrace());
        collapsingToolbarLayout.setContentScrimColor(
                ContextCompat.getColor(this, R.color.primary_500)
        );
        collapsingToolbarLayout.setStatusBarScrimColor(
                ContextCompat.getColor(this, R.color.primary_700)
        );
    }

    tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
        @Override
        public void onTabSelected(TabLayout.Tab tab) {

            viewPager.setCurrentItem(tab.getPosition());
            Log.d(TAG, "onTabSelected: pos: " + tab.getPosition());

            switch (tab.getPosition()) {
                case 0:
                    // TODO: 31/03/17
                    break;
            }
        }

        @Override
        public void onTabUnselected(TabLayout.Tab tab) {

        }

        @Override
        public void onTabReselected(TabLayout.Tab tab) {

        }
    });
}

private void setupViewPager(ViewPager viewPager) {
    ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
    adapter.addFrag(new DummyFragment(
            ContextCompat.getColor(this, R.color.cyan_50)), "Cyan");
    adapter.addFrag(new DummyFragment(
            ContextCompat.getColor(this, R.color.amber_50)), "Amber");
    adapter.addFrag(new DummyFragment(
            ContextCompat.getColor(this, R.color.purple_50)), "Purple");
    adapter.addFrag(new DummyFragment(
            ContextCompat.getColor(this, R.color.grey)), "Grey");
    viewPager.setAdapter(adapter);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);

    MenuItem menuItem = menu.findItem(R.id.menuSearch);
    SearchView searchView = (SearchView) MenuItemCompat.getActionView(menuItem);
    searchView.setOnQueryTextListener(this);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case android.R.id.home:
            finish();
            return true;
        case R.id.menuSearch:
            return true;
    }
    return super.onOptionsItemSelected(item);
}

@Override
public boolean onQueryTextSubmit(String query) {
    return false;
}

@Override
public boolean onQueryTextChange(String newText) {

    newText = newText.toLowerCase();
    ArrayList<Dessert> newList = new ArrayList<>();

    for(Dessert dessert : Dessert.desserts){
        String name = dessert.getName().toLowerCase();
        if(name.contains(newText)){
            newList.add(dessert);
        }
    }

    new DessertAdapter(getBaseContext()).setFilter(newList);
    return true;
}

private static 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 addFrag(Fragment fragment, String title) {
        mFragmentList.add(fragment);
        mFragmentTitleList.add(title);
    }

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

    @Override
    public int getItemPosition(Object object) {
        return POSITION_NONE;
    }
}

public static class DummyFragment extends Fragment{
    int color;
    Intent intent;
    DessertAdapter adapter;

    public DummyFragment() {
    }

    @SuppressLint("ValidFragment")
    public DummyFragment(int color) {
        this.color = color;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.dummy_fragment, container, false);

        final FrameLayout frameLayout = (FrameLayout) view.findViewById(R.id.dummyfrag_bg);
        frameLayout.setBackgroundColor(color);

        RecyclerView recyclerView = (RecyclerView) view.findViewById(R.id.dummyfrag_scrollableview);

        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getActivity().getBaseContext());
        recyclerView.setLayoutManager(linearLayoutManager);
        recyclerView.setHasFixedSize(true);

        adapter = new DessertAdapter(getContext());
        recyclerView.setAdapter(adapter);
return view;
    }

}
}

Answer 1

您正在新的DessertAdapter实例上调用set filter，而不是您在recyclerview中设置的适配器实例。

您应该在DummyFragment中定义一个接口，允许活动向其提供搜索视图查询。

然后在已经在片段中实例化的DessertAdapter实例上调用setFilter。

notifyDataSetChanged（）不适用于SearchView

1 个答案: