Target: Trying to pass data from FragmentA to Activity to FragmentB using an interface.
Issue: FragmentB is not being .replaced (created) in Fragment a when clicking on bottom. (Also tried .add) The only way to go around this is to start both fragments when the Activity is created.
Path: activity -> fragmentA -> onclick replace fragment and pass data with interface -> activty -> pass data from activity to Fragment B.
Tried:
.Replace and .Add, fragmentb in activty and in fragmentA
Main Activity:
public class MainActivity extends AppCompatActivity implements Communicator {
android.support.v4.app.FragmentTransaction ft;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
AFragment savedFragment = (AFragment)
getSupportFragmentManager().findFragmentById(R.id.fl_conainter);
if (savedFragment == null) {
addFragment();
}
}
private void addFragment() {
ft = getSupportFragmentManager().beginTransaction();
AFragment aFragment = new AFragment();
ft.add(R.id.fl_conainter,aFragment,"FragA");
ft.commit();
}
//****Issue is here ****
#Override
public void respond(String value) {
addSecondFragment();
FragmentManager manager=getSupportFragmentManager();
/* BFragment fragment = (BFragment)
manager.findFragmentById(R.id.fragmentB);*/
BFragment fragment = (BFragment) manager.findFragmentByTag("Fragb");
fragment.changeData(value);
}
private void addSecondFragment() {
BFragment bFragment = new BFragment();
ft = getSupportFragmentManager().beginTransaction();
ft.replace(R.id.fl_conainter,bFragment,"Fragb");
ft.commit();
}
}
Fragment A:
public class AFragment extends Fragment implements View.OnClickListener {
Communicator communicator;
Button button;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_a, container, false);
}
#Override
public void onActivityCreated (Bundle saveInstanceState) {
super.onActivityCreated(saveInstanceState);
button = getActivity().findViewById(R.id.update_btn);
button.setOnClickListener(this);
communicator = (Communicator) getActivity();
}
#Override
public void onClick(View view) {
// AddNextfrag();
communicator.respond("passing data");
}
private void AddNextfrag (){
android.support.v4.app.FragmentTransaction ft;
ft = getActivity().getSupportFragmentManager().beginTransaction();
BFragment bFragment = new BFragment();
ft.add(R.id.fl_conainter,bFragment, "Fragb");
ft.commit();
}
}
Fragment B:
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class BFragment extends Fragment {
TextView text;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_b, container, false);
}
#Override
public void onActivityCreated (Bundle saveInstanceState) {
super.onActivityCreated(saveInstanceState);
text = getActivity().findViewById(R.id.result_tv);
}
public void changeData(String value){
text.setText(value);
}
}
Interface:
public interface Communicator {
void respond(String value);
}
public class AFragment extends Fragment implements
View.OnClickListener {
Communicator communicator;
Button button;
Activity activity;
#Override
public void onAttach(Activity activity)
{
super.onAttach(activity);
this.activity = activity;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_a, container, false);
}
#Override
public void onActivityCreated (Bundle saveInstanceState) {
super.onActivityCreated(saveInstanceState);
button = getActivity().findViewById(R.id.update_btn);
button.setOnClickListener(this);
communicator = (Communicator) activity ;
}
#Override
public void onClick(View view) {
// AddNextfrag();
communicator.respond("passing data");
}
private void AddNextfrag (){
android.support.v4.app.FragmentTransaction ft;
ft = getActivity().getSupportFragmentManager().beginTransaction();
BFragment bFragment = new BFragment();
ft.add(R.id.fl_conainter,bFragment, "Fragb");
ft.commit();
}
}
Related
I am trying to replace the current active fragment inside ViewPager when item inside fragment's recycelerview is clicked. So far, I manage to pop up the Toast on the second fragment when the item on the first fragment is clicked, but the all the view of the second fragment is blank.
Here is my code:
MainActivity.class
public class MainActivity extends AppCompatActivity {
private ViewPager viewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
viewPager = findViewById(R.id.view_pager);
FragmentAdapter adapter = new FragmentAdapter(getSupportFragmentManager());
viewPager.setAdapter(adapter);
viewPager.setOffscreenPageLimit(adapter.getCount() - 1);
}
// ..........
private static class FragmentAdapter extends FragmentStatePagerAdapter {
public FragmentAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return AllGenreFragment.newInstance();
case 1:
return DashboardFragment.newInstance();
case 2:
return NotificationFragment.newInstance();
}
return null;
}
#Override
public int getCount() {
return 3;
}
}
// ..........
}
AllGenreFragment.class
public class AllGenreFragment extends Fragment {
RecyclerView genreRV;
private AllGenreAdapter allGenreAdapter;
private List<Genre> genreList;
public static AllGenreFragment newInstance() {
return new AllGenreFragment();
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
setHasOptionsMenu(true);
}
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_genre, container, false);
genreRV = v.findViewById(R.id.rv);
genreRV.setHasFixedSize(true);
GridLayoutManager layoutManager = new GridLayoutManager(getContext(), 2);
genreRV.setLayoutManager(layoutManager);
genreList = new ArrayList<>();
allGenreAdapter = new AllGenreAdapter(genreList, getContext());
genreRV.setAdapter(allGenreAdapter);
return v;
}
}
AllGenreAdapter.class
public class AllGenreAdapter extends RecyclerView.Adapter<AllGenreAdapter.ViewHolder> {
// .......
class ViewHolder extends android.support.v7.widget.RecyclerView.ViewHolder {
public ViewHolder(final View itemView) {
super(itemView);
itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(context, "Genre: " + genre_title.getText().toString(), Toast.LENGTH_SHORT).show();
AppCompatActivity activity = (AppCompatActivity) itemView.getContext();
FragmentManager fragmentManager = activity.getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
Fragment allAnimeFragment = new AllAnimeFragment();
Bundle bundle = new Bundle();
bundle.putString("genreid", genre_id.getText().toString().trim());
allAnimeFragment.setArguments(bundle);
fragmentTransaction.replace(R.id.view_pager, allAnimeFragment);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
}
});
}
}
// .......
}
AllAnimeFragment.class
public class AllAnimeFragment extends Fragment {
RecyclerView animeRV;
private AllAnimeAdapter allAnimeAdapter;
private List<Anime> animeList;
String genreid;
public static AllAnimeFragment newInstance() {
return new AllAnimeFragment();
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
setHasOptionsMenu(true);
}
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_anime, container, false);
Bundle arguments = getArguments();
genreid = arguments.getString("genreid");
Toast.makeText(getContext(), genreid, Toast.LENGTH_SHORT).show();
// .....
return v;
}
}
Your approach is not really good, try below way:
Create a container fragment, called ContainerFragment, example, you will be using this fragment for your ViewPager.
The ContainerFragment should contain a container view, and add AllGenreFragment in the first them it is invoked.
In AllGenreFragment, create a callback, when an item in the RecyclerView be clicked, then in ContainerFragment will replace (or add) current fragment (AllGenreFragment) to AllAnimeFragment
First, create ContainerFragment,
public class ContainerFragment extends Fragment implements AllGenreFragment.OnAllGenreFragmentListener {
#Nullable #Override public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_container, container, false);
}
#Override public void onViewCreated(View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
initialLoad();
}
private void initialLoad() {
getChildFragmentManager()
.beginTransaction()
.add(R.id.container, AllGenreFragment.newInstance())
.commit();
}
#Override public void onItemClicked() {
getChildFragmentManager()
.beginTransaction()
.replace(R.id.container, AllAnimeFragment.newInstance())
.commit();
}
}
This Fragment should implement a callback from AllGenreFragment for handling fragment transaction.
also, the xml layout
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent" />
Next step, add above fragment into ViewPager, we using ContainerFragment instead of AllGenreFragment.
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return ContainerFragment().newInstance();
case 1:
return DashboardFragment.newInstance();
case 2:
return NotificationFragment.newInstance();
}
return null;
}
Ok, so now come back to AllGenreFragment, we should create a CallBack that we implement in ContainerFragment
public interface AllGenreFragmentListener {
onItemClicked();
}
and then,
private AllGenreFragmentListener listener;
#Override public void onAttach(Context context) {
super.onAttach(context);
if (getParentFragment() instanceof AllGenreFragmentListener) {
listener = (AllGenreFragmentListener) getParentFragment();
}
}
so we have an instance of AllGenreFragmentListener, from now, whenever listener call onItemClicked, the method onItemClicked in ContainerFragment will be invoked.
Ok, let do it,
create below variable and method in your AllGenreAdapter:
private AllGenreFragmentListener listener;
public void setListener(AllGenreFragmentListener listener) {
this.listener = listener;
}
and update your ViewHodler
itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(context, "Genre: " + genre_title.getText().toString(), Toast.LENGTH_SHORT).show();
if (listener != null)
listener.onItemClicked()
});
}
Don't forget call setListener method in your AllGenreFragment, so please add
#Override public void onViewCreated(#NonNull View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
if (allGenreAdapter != null) allGenreAdapter.setListener(listener);
}
That all,
I type this code by hand, not in my IDE so maybe it not compile, so please fix it if you face any compile error.
Note
If you want to keep the behavior of the BACK button, override onBackPressed in your MainActivity
#Override public void onBackPressed() {
Fragment f = getCurrentFragment();
if (f != null) {
if (f.getChildFragmentManager().getBackStackEntryCount() > 1) {
f.getChildFragmentManager().popBackStack();
} else {
super.onBackPressed();
}
} else {
super.onBackPressed();
}
}
public Fragment getCurrentFragment() {
return (Fragment) viewPager.getAdapter()
.instantiateItem(viewPager, viewPager.getCurrentItem());
}
Also, add fragment into backStack whenever we add them to the container view (in your ContainerFragment)
private void initialLoad() {
getChildFragmentManager()
.beginTransaction()
.add(R.id.container, AllGenreFragment.newInstance())
.addToBackStack(null)
.commit();
}
#Override public void onItemClicked() {
// change `replace` to `add` and add more `.addToBackStack(null)`
getChildFragmentManager()
.beginTransaction()
.add(R.id.container, AllAnimeFragment.newInstance())
.addToBackStack(null)
.commit();
}
you should add a context in the constructor of your adapter
public class AllGenreAdapter(Context context) extends RecyclerView.Adapter<AllGenreAdapter.ViewHolder> {
// .......
}
then pass your activity to your adapter, use it to replace your fragment
I am frustrated.
i want to get value from child fragment to parent fragment
i had tries many method.
interface, viewModel, sharedpreferences but no one work.
I had follow this method
but it doesn't work for me.
here my code parent fragment:
public class Chart_Fragment extends Fragment
implements Product_Fragment.pf_interface {
String dt;
TextView tv;
public Chart_Fragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View v = inflater.inflate(R.layout.chart_fragment, container, false);
// create product_fragment as childfragment
FragmentManager fm = getChildFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
Product_Fragment product_fragment = new Product_Fragment();
ft.replace(R.id.fl_two, new Product_Fragment());
ft.commit();
return v;
}
public void onViewCreated(View v, Bundle savedInstanceState){
super.onViewCreated(v,savedInstanceState);
tv = (TextView)v.findViewById(R.id.rcv);
}
#Override
public void data(String d) {
FragmentManager fragmentManager = getChildFragmentManager();
Product_Fragment product_fragment =
(Product_Fragment)fragmentManager.findFragmentByTag("data");
if(product_fragment != null){
String dt = d;
tv.setText(dt);
}
}
}
and my childfragment is :
public class Product_Fragment extends Fragment {
private pf_interface pf;
public Product_Fragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View v = inflater.inflate(R.layout.product_fragment, container, false);
Button b = (Button)v.findViewById(R.id.btn_sender);
b.setOnClickListener(new btnClick());
return v;
}
public void onAttachToParentFragment(Fragment fragment){
try {
pf = (pf_interface)fragment;
}catch (ClassCastException e){
throw new ClassCastException(
fragment.toString()+ "must implement pf_interface"
);
}
}
public void onCreate(Bundle savedInstanceState){
Log.i(TAG, "onCreate");
super.onCreate(savedInstanceState);
onAttachToParentFragment(getParentFragment());
}
private class btnClick implements View.OnClickListener{
#Override
public void onClick(View v) {
switch (v.getId()){
case R.id.btn_sender:
if(pf != null){
pf.data("button click interface");
}break;
}
}
}
public interface pf_interface{
void data(String d);
}
}
textview on parent fragment didn't show the string d ("button click interface")from child fragment
Why you're checking for child fragment in callback on your parent fragment ?
#Override
public void data(String d) {
FragmentManager fragmentManager = getChildFragmentManager();
Product_Fragment product_fragment =
(Product_Fragment)fragmentManager.findFragmentByTag("data");
if(product_fragment != null){ // Why to check for child fragment nullability?
String dt = d;
tv.setText(dt);
}
}
You can directly use like this:
#Override
public void data(String d) {
tv.setText(d);
}
Note: on any certain scenario if any of object is null, your callback won't be executed. You've already check for null reference.
I cant pass the data from FragmentOne to FragmentTwo it only move to FragmentTwo without the text i already type it in the edit text in FragmentOne i did my search but i cant any solution that can fix the error.
This is the MainActivity
public class FragmentExampleAct extends AppCompatActivity implements FragmentOne.OnNameSetListener {
RelativeLayout rl;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_fragment_example);
rl=(RelativeLayout)findViewById(R.id.rlTwo);
FragmentOne f1=new FragmentOne();
getSupportFragmentManager().beginTransaction().replace(R.id.rlTwo,f1).commit();
}
#Override
public void setName(String name) {
FragmentTwo fragment = (FragmentTwo) getSupportFragmentManager().findFragmentById(R.id.f2);
if(fragment !=null)
{
fragment.updateName(name);
}
else
{
FragmentTwo fragmentTwo=new FragmentTwo();
Bundle args=new Bundle();
args.putString("text",name);
fragmentTwo.setArguments(args);
getSupportFragmentManager().beginTransaction().replace(R.id.rlTwo,fragmentTwo).addToBackStack(null).commit();
//fragmentTwo.updateName(name);
}
}
}
This is FragmentOne
public class FragmentOne extends Fragment implements View.OnClickListener{
Button btn;
EditText etName;
OnNameSetListener onNameSetListener;
public FragmentOne() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View v= inflater.inflate(R.layout.fragment_fragment_one, container, false);
btn=(Button) v.findViewById(R.id.button4);
etName=(EditText) v.findViewById(R.id.editText5);
btn.setOnClickListener(this);
return v;
}
#Override
public void onClick(View view) {
String name=etName.getText().toString();
onNameSetListener.setName(name);
FragmentTwo f2=new FragmentTwo();
replaceFragment(f2);
}
public void replaceFragment(Fragment fragment)
{
FragmentTransaction trans=getActivity().getSupportFragmentManager().beginTransaction();
trans.replace(R.id.rlTwo,fragment);
trans.addToBackStack(null);
trans.commit();
}
public interface OnNameSetListener
{
public void setName(String name);
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
try {
onNameSetListener =(OnNameSetListener)getActivity();
}
catch (ClassCastException e)
{
throw new ClassCastException(context.toString()+ " must implement OnImageClickListener");
}
}
}
This is FragmentTwo
public class FragmentTwo extends Fragment {
TextView tv;
public FragmentTwo() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View v= inflater.inflate(R.layout.fragment_fragment_two, container, false);
tv=(TextView) v.findViewById(R.id.tv7);
return v;
}
public void updateName (String name){
tv.setText("Welcome"+name);
}
}
I have three fragment and one activity. It works this way:
[activity]-> [MainFragment]->[MenuFragment]->[SignUpFragment]
When [SignUpFragment] is back pressed, the [MainFragment] is created twice.
I tried setRetaInInstance(true) and I checked savedInstanceState but I can not prevent [MainFragment] recreating.
This is my MainActivity:
public class MainActivity extends AppCompatActivity {
public Bundle mSavedInstanceState;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mSavedInstanceState = savedInstanceState;
setContentView(R.layout.activity_main);
}
#Override
protected void onResume() {
super.onResume();
callMainFragment();
}
private void callMainFragment() {
if (mSavedInstanceState == null) {
FragmentManager manager = getSupportFragmentManager();
FragmentTransaction transaction = manager.beginTransaction();
transaction.replace(R.id.container_category, new MainFragment(), MainFragment.class.getSimpleName());
transaction.addToBackStack(null);
transaction.commit();
}
}
public ActionBar getMainActionBar(){
ActionBar actionBar = getSupportActionBar();
if (actionBar != null) {
// Action Bar Display settings
actionBar.setDisplayShowCustomEnabled(true);
actionBar.setDisplayShowTitleEnabled(false);
// Custom view inflater
LayoutInflater inflater = (LayoutInflater) this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
// Custom layout view
View viewActionBar = inflater.inflate(R.layout.action_bar, null);
// Set custom view
actionBar.setCustomView(viewActionBar);
actionBar.setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM);
}
return actionBar;
}
This is my MainFragment:
public class MainFragment extends BaseFragment implements AdapterView.OnItemClickListener, BuyersGuideCategoriesDelegate, View.OnClickListener {
private Bundle mSavedInstanceState;
private BuyersGuideCategoriesFragment mCategoriesFragment;
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.setRetainInstance(true);
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
mSavedInstanceState = savedInstanceState;
if (mSavedInstanceState == null) {
mView = inflater.inflate(R.layout.fragment_main, container, false);
// Call Grid View Buyers Guide Fragment
mCategoriesFragment = new BuyersGuideCategoriesFragment();
mCategoriesFragment.mGridViewDelegate = this;
setIcons();
setTitles();
setTexts();
initListView();
}
return mView;
}
#Override
public void onResume() {
super.onResume();
ImageView menu = (ImageView) ((MainActivity) getActivity()).getMainActionBar().getCustomView().findViewById(R.id.action_bar_menu_icon);
menu.setOnClickListener(this);
}
#Override
public void onClick(View v) {
if (mSavedInstanceState == null) {
MainActivity activity = (MainActivity) getActivity();
FragmentManager manager = activity.getSupportFragmentManager();
FragmentTransaction transaction = manager.beginTransaction();
transaction.replace(R.id.container_category, new MenuFragment(),MenuFragment.class.getSimpleName());
transaction.addToBackStack(null);
transaction.commit();
}
}
}
This is my MenuFragment:
public class MenuFragment extends BaseFragment implements AdapterView.OnItemClickListener, View.OnClickListener {
private Bundle mSavedInstanceState;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
mSavedInstanceState = savedInstanceState;
if (savedInstanceState == null) {
mView = inflater.inflate(R.layout.fragment_menu, container, false);
setMenuItemsListViewAdapter();
}
return mView;
}
private void setMenuItemsListViewAdapter() {
ListView menuItems = (ListView) mView.findViewById(R.id.list_menu_items);
ListMenuItemsListViewAdapter adapter = new ListMenuItemsListViewAdapter(getContext(),getMenuItemNames());
menuItems.setAdapter(adapter);
menuItems.setOnItemClickListener(this);
}
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
switch ((String) parent.getAdapter().getItem(position)){
case SIGN_UP:
replaceFragment(R.id.container_category,new SignUpFragment(),SignUpFragment.class.getSimpleName());
break;
}
}
private void replaceFragment(int containerId,Fragment fragment, String fragmentTag){
if (mSavedInstanceState == null){
MainActivity activity = (MainActivity) getActivity();
FragmentManager manager = activity.getSupportFragmentManager();
FragmentTransaction transaction = manager.beginTransaction();
transaction.replace(containerId,fragment,fragmentTag);
transaction.addToBackStack(null);
transaction.commit();
}
}
#Override
public void onClick(View v) {
switch (v.getId()){
case R.id.menu_back_icon:
replaceFragment(R.id.container_category, new MainFragment(),MainFragment.class.getSimpleName());
break;
}
}
}
And this is my SignUpFragment:
public class SignUpFragment extends BaseFragment implements View.OnClickListener{
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
if (savedInstanceState == null) {
mView = inflater.inflate(R.layout.fragment_sign_up, container, false);
}
return mView;
}
}
EDIT 1: The MainFragment is recreated only when I return from SignUpFragment to MenuFragment. I am doing wrong using so many fragments? Should I use activity?
When you are move between Fragments, call addToBackStack() :
FragmentTransaction ft = fragmentManager.beginTransation();
ft.replace( R.id.fragment, new MyFragment() ).addToBackStack( "ftransaction" ).commit();
Create first Fragment:
FragmentTransaction ft = fragmentManager.beginTransation();
ft.add(R.id.container, new FirstFragment()).addToBackStack(null).commit();
Second:
FragmentTransaction ft = fragmentManager.beginTransation();
ft.replace(R.id.container, new SecondFragment()).addToBackStack(null).commit();
and Third:
FragmentTransaction ft = fragmentManager.beginTransation();
ft.replace(R.id.container, new ThirdFragment()).commit();
In my MainActivity there is a FrameLayout (id=fragment_container) that is replaced by the Activity in onCreate with FragmentA. FragmentA just contains a single Button and calls onClick in the MainActivity in order to replace the FrameLayout with FragmentB. FragmentB contains a RecyclerView and is shown correctly. I call fragmentManager.popBackStack() to bring back FragmentA. Now FragmentA is shown on top of FragmentB (which I still can interact with).
Why is FragmentB not removed after calling popBackStack?
MainActivity
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
private FragmentManager fragmentManager;
#Override
public void onBackPressed() {
fragmentManager.popBackStack();
}
#Override
public void onClick(View view) {
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.fragment_container, new FragmentB());
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//...
fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
FragmentA fragment = FragmentA.getInstance(this); //register OnClickListener
fragmentTransaction.replace(R.id.fragment_container, fragment);
fragmentTransaction.commit();
}
//...
}
FragmentA
public class FragmentA extends Fragment {
private View.OnClickListener onClickListener;
public FragmentA() {
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_a, container, false);
FloatingActionButton fab = (FloatingActionButton) view.findViewById(R.id.fab);
fab.setOnClickListener(onClickListener);
return view;
}
public static FragmentA getInstance(View.OnClickListener onClickListener) {
FragmentA fragmentA = new FragmentA();
fragmentA.setOnClickListener(onClickListener);
return fragmentA;
}
private void setOnClickListener(View.OnClickListener onClickListener) {
this.onClickListener = onClickListener;
}
}
FragmentB
public class FragmentB extends Fragment {
//...
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.FragmentB, container, true);
//manipulating Views...
//...
return view;
}
}
The problem is in the FragmentB class. You should not pass the argument attachToRoot=true.
Try this instead:
public class FragmentB extends Fragment {
//...
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
//don't pass true
View view = inflater.inflate(R.layout.FragmentB, container, false);
//manipulating Views...
//...
return view;
}
}
Use popBackStackImmediate instead,
#Override
public void onBackPressed() {
fragmentManager.popBackStackImmediate();
}
From the popBackStackImmediate docs,
Like popBackStack(), but performs the operation immediately inside of the call. This is like calling executePendingTransactions() afterwards.