我正在使用带有滑动标签的材料设计导航抽屉，我已经实现了相同的功能。
现在，我想在其中一个标签片段中添加cardview recycler view，但不知道该怎么做。
请有人帮我这个吗？
这是我的标签片段代码： -
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;
}
}
}
这是我的片段类，其中我添加了recycleler视图，但是在设置适配器时它给了NULL Point exception。
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();
}
}
这是我的 recyclerview类： -
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();
}
我想在cardview片段中添加recycler view Favourite。我知道如何实现cardview但无法在片段中实现它。
答案 0 :(得分：3)
首先在主要活动中进行更改。 这里我在mainactivity中添加了一个导航抽屉和tablayout。
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;
}
}
然后创建一个寻呼机适配器。 在这里你可以为你的标签添加片段.. 我把它命名为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;
}
}
我只想在第一个标签页中找到一个Recycler视图。所以我在HomeTabFragment1.java中添加了recyclerview的代码。
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;
我希望你能做的其余的事情......
答案 1 :(得分：0)
看起来像是＆＃34; rv＆＃34;永远不会在FavouriteFragment类中初始化，你确实初始化了局部变量＆＃34; rv＆＃34;在方法onCreateView。
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;
}