Cardview tab inner fragment

Question

I am working on a drawer for material design with sliding tabs, and I have implemented the same. Now I want to add a cardview with a recycler view inside one of the tab fragments, but I don’t know how to do it.

Please help me with this?

Here is my fragment snippet :

  public class TabFragment extends Fragment { public static TabLayout tabLayout; public static ViewPager viewPager; public static int int_items = 2 ; @Nullable @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { /** *Inflate tab_layout_tens and setup Views. */ View x = inflater.inflate(R.layout.tab_layout_tens,null); tabLayout = (TabLayout) x.findViewById(R.id.tabs); viewPager = (ViewPager) x.findViewById(R.id.viewpager); /** *Set an Apater for the View Pager */ viewPager.setAdapter(new MyAdapter(getChildFragmentManager())); /** * Now , this is a workaround , * The setupWithViewPager dose't works without the runnable . * Maybe a Support Library Bug . */ tabLayout.post(new Runnable() { @Override public void run() { tabLayout.setupWithViewPager(viewPager); } }); return x; } class MyAdapter extends FragmentPagerAdapter{ public MyAdapter(FragmentManager fm) { super(fm); } /** * Return fragment with respect to Position . */ @Override public Fragment getItem(int position) { switch (position){ case 0 : return new CurrentFragment(); case 1 : return new FavouriteFragment(); } return null; } @Override public int getCount() { return int_items; } /** * This method returns the title of the tab according to the position. */ @Override public CharSequence getPageTitle(int position) { switch (position){ case 0 : return "Current"; case 1 : return "Favourite"; } return null; } } } 

And this is my fragment class in which I added a recycler view, but it gives a NULL Point exception when configuring the adapter.

  public class FavouriteFragment extends Fragment { private List<Person> persons; private RecyclerView rv; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); } @Nullable @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View rootView = inflater.inflate(R.layout.favourite_layout,container,false); RecyclerView rv = (RecyclerView)rootView.findViewById(R.id.rv); final LinearLayoutManager llm = new LinearLayoutManager(getActivity()); rv.setLayoutManager(llm); initializeData(); initializeAdapter(); return rootView; } private void initializeData(){ persons = new ArrayList<>(); persons.add(new Person("XYZ", "jhxdjksd", R.drawable.profilepic)); persons.add(new Person("ABC", "bsxhbs", R.drawable.profilepic)); persons.add(new Person("PQR", "bsahxb", R.drawable.profilepic)); } private void initializeAdapter(){ RVAdapter adapter = new RVAdapter(persons); rv.setAdapter(adapter); } } 

Mainactivity

  public class Tens extends AppCompatActivity { DrawerLayout mDrawerLayout; NavigationView mNavigationView; FragmentManager mFragmentManager; FragmentTransaction mFragmentTransaction; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_tens); /** *Setup the DrawerLayout and NavigationView */ mDrawerLayout = (DrawerLayout) findViewById(R.id.drawerLayout); mNavigationView = (NavigationView) findViewById(R.id.shitstuff) ; /** * Lets inflate the very first fragment * Here , we are inflating the TabFragmentTens as the first Fragment */ mFragmentManager = getSupportFragmentManager(); mFragmentTransaction = mFragmentManager.beginTransaction(); mFragmentTransaction.replace(R.id.containerView,new TabFragmentTens()).commit(); /** * Setup click events on the Navigation View Items. */ mNavigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() { @Override public boolean onNavigationItemSelected(MenuItem menuItem) { Fragment fragment = null; Class fragmentClass = null; switch(menuItem.getItemId()) { case R.id.nav_item_tracker: Intent intent = new Intent( Tens.this, Tracker.class); startActivity(intent); break; case R.id.nav_item_clinic: fragmentClass = ClinicFragment.class; break; case R.id.nav_item_about: Intent intent0 = new Intent( Tens.this, AboutFragment.class); startActivity(intent0); break; case R.id.nav_item_settings: Intent intent1 = new Intent( Tens.this, SettingsFragment.class); startActivity(intent1); break; case R.id.nav_item_logout: Intent intent2 = new Intent( Tens.this, MainActivity.class); startActivity(intent2); break; } try { fragment = (Fragment) fragmentClass.newInstance(); } catch (Exception e) { e.printStackTrace(); } FragmentTransaction xfragmentTransaction = mFragmentManager.beginTransaction(); xfragmentTransaction.replace(R.id.containerView, new TabFragmentTens()).commit(); mDrawerLayout.closeDrawers(); return false; } }); android.support.v7.widget.Toolbar toolbar = (android.support.v7.widget.Toolbar) findViewById(R.id.toolbar); ActionBarDrawerToggle mDrawerToggle = new ActionBarDrawerToggle(this,mDrawerLayout, toolbar,R.string.app_name, R.string.app_name); mDrawerLayout.setDrawerListener(mDrawerToggle); mDrawerToggle.syncState(); } } 

Here is my recyclerview class : -

  public class RVAdapter extends RecyclerView.Adapter<RVAdapter.PersonViewHolder> { public static class PersonViewHolder extends RecyclerView.ViewHolder { CardView cv; TextView personName; TextView personAge; ImageView personPhoto; PersonViewHolder(View itemView) { super(itemView); cv = (CardView)itemView.findViewById(R.id.cv); personName = (TextView)itemView.findViewById(R.id.person_name); personAge = (TextView)itemView.findViewById(R.id.person_age); personPhoto = (ImageView)itemView.findViewById(R.id.person_photo); } } List<Person> persons; RVAdapter(List<Person> persons){ this.persons = persons; } @Override public void onAttachedToRecyclerView(RecyclerView recyclerView) { super.onAttachedToRecyclerView(recyclerView); } @Override public PersonViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) { View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.card_view_tens_fvrt, viewGroup, false); PersonViewHolder pvh = new PersonViewHolder(v); return pvh; } @Override public void onBindViewHolder(PersonViewHolder personViewHolder, int i) { personViewHolder.personName.setText(persons.get(i).name); personViewHolder.personAge.setText(persons.get(i).age); personViewHolder.personPhoto.setImageResource(persons.get(i).photoId); } @Override public int getItemCount() { return persons.size(); } 

I want to add a cardview with a recycler view inside the Favourite fragment. I know how to implement cardview , but could not implement it inside fragments.

Answer 1

make changes in your primary activity first. here I added a navigation box and tablayout to mainactivity.

 public class HomeActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_home); Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); setSupportActionBar(toolbar); DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); ActionBarDrawerToggle toggle = new ActionBarDrawerToggle( this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close); drawer.setDrawerListener(toggle); toggle.syncState(); NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view); navigationView.setNavigationItemSelectedListener(this); TabLayout tabLayout1 = (TabLayout) findViewById(R.id.tab_layout1); tabLayout1.addTab(tabLayout1.newTab().setIcon(R.drawable.tab_ic_home)); tabLayout1.addTab(tabLayout1.newTab().setIcon(R.drawable.tab_ic_map)); tabLayout1.addTab(tabLayout1.newTab().setIcon(R.drawable.tab_ic_login)); tabLayout1.setTabGravity(TabLayout.GRAVITY_FILL); final ViewPager viewPager1 = (ViewPager) findViewById(R.id.pager1); final PagerAdapter1 adapter = new PagerAdapter1 (getSupportFragmentManager(), tabLayout1.getTabCount()); viewPager1.setAdapter(adapter); viewPager1.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout1)); tabLayout1.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() { @Override public void onTabSelected(TabLayout.Tab tab) { viewPager1.setCurrentItem(tab.getPosition()); } @Override public void onTabUnselected(TabLayout.Tab tab) { } @Override public void onTabReselected(TabLayout.Tab tab) { } }); } @Override public void onBackPressed() { DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); if (drawer.isDrawerOpen(GravityCompat.START)) { drawer.closeDrawer(GravityCompat.START); } else { super.onBackPressed(); } } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.home, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { // Handle action bar item clicks here. The action bar will // automatically handle clicks on the Home/Up button, so long // as you specify a parent activity in AndroidManifest.xml. int id = item.getItemId(); //noinspection SimplifiableIfStatement if (id == R.id.action_settings) { return true; } return super.onOptionsItemSelected(item); } @SuppressWarnings("StatementWithEmptyBody") @Override public boolean onNavigationItemSelected(MenuItem item) { FragmentManager fragmentManager = getSupportFragmentManager(); FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction(); // Handle navigation view item clicks here. int id = item.getItemId(); RelativeLayout mainLayout=(RelativeLayout)findViewById(R.id.main_layout); if (id == R.id.nav_project) { ProjectFragment fragment = new ProjectFragment(); fragmentTransaction.replace(R.id.mainlayout, fragment); fragmentTransaction.addToBackStack(null).commit(); } } DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); drawer.closeDrawer(GravityCompat.START); return true; } } 

Then create a pager adapter. here you can add snippets for your tabs. I called it PagerAdapter1.java.

  import android.support.v4.app.Fragment; import android.support.v4.app.FragmentManager; import android.support.v4.app.FragmentStatePagerAdapter; public class PagerAdapter1 extends FragmentStatePagerAdapter { int mNumOfTabs; public PagerAdapter1(FragmentManager fm, int NumOfTabs) { super(fm); this.mNumOfTabs = NumOfTabs; } @Override public Fragment getItem(int position) { switch (position) { case 0: HomeTabFragment1 tab1 = new HomeTabFragment1(); return tab1; case 1: HomeTabFragment2 tab2 = new HomeTabFragment2(); return tab2; case 2: HomeTabFragment3 tab3 = new HomeTabFragment3(); return tab3; default: return null; } } @Override public int getCount() { return mNumOfTabs; } } 

I just need a Recycler view on the first tab. So I added the code for recyclerview to HomeTabFragment1.java.

 public class HomeTabFragment1 extends Fragment { @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View v=inflater.inflate(R.layout.home_tab_fragment_1, container, false); RecyclerView rv = (RecyclerView)v.findViewById(R.id.home_recyclerview); setupRecyclerView(rv); return v; 

I hope the rest can be done.

Answer 2

It looks like the "rv" field is never initialized in the FavoriteFragment class, you initialized the local variable "rv" in the onCreateView method.

 public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View rootView = inflater.inflate(R.layout.favourite_layout,container,false); RecyclerView rv = (RecyclerView)rootView.findViewById(R.id.rv); final LinearLayoutManager llm = new LinearLayoutManager(getActivity()); rv.setLayoutManager(llm); initializeData(); initializeAdapter(); return rootView; }