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How to get value from childfragment to parentfragment?

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.

Fragments in ViewPager is not displayer after popBackStack

I have problem: A Fragment is not reattached to its hosting ViewPager after returning from another fragment by using popBackStack.
One Activity hosting a Fragment whose layout holds a ViewPager. The ViewPager is populated by a FragmentStateViewPagerAdapter. The Fragment hosted inside the pager can open sub page lists, containing a new set of pages. All works fine as long as the back button is not pressed. As soon as the user closes one of the sub Page the previous Page is recreated, but without the Page that was displayed previously (Empty page with whiteblank page). I have searching but still not resolve my problem.
Full Code of TestProject can be found on Github
MainActivity:
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val ft = supportFragmentManager.beginTransaction()
ft.add(R.id.frameLayout, HomeFragment.newInstance())
ft.commit()
}
}
HomeFragment:
public class HomeFragment extends Fragment {
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_home, container, false);
TabLayout tabLayout = v.findViewById(R.id.tabLayout);
ViewPager viewPager = v.findViewById(R.id.viewPager);
VPAdapter adapter = new VPAdapter(getFragmentManager());
viewPager.setAdapter(adapter);
tabLayout.setupWithViewPager(viewPager);
return v;
}
public static Fragment newInstance() {
return new HomeFragment();
}
}
VPAdapter:
public class VPAdapter extends FragmentStatePagerAdapter{
public VPAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
return TabFragment.newInstance(position);
}
#Override
public CharSequence getPageTitle(int position) {
return "TAB " + position;
}
#Override
public int getCount() {
return 2;
}
}
TabFragment:
public class TabFragment extends Fragment {
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.e("TAB", "onCreate");
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
Log.e("TAB", "onCreateView");
return inflater.inflate(R.layout.fragment_tab, container, false);
}
#Override
public void onViewCreated(View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
Bundle args = getArguments();
if (args != null) {
int tabIndex = args.getInt("tab_index", 0);
TextView tv = view.findViewById(R.id.textView);
tv.setText(String.format(Locale.getDefault(), "TAB FRAGMENT INDEX %d", tabIndex));
}
Button button = view.findViewById(R.id.button);
button.setText("Open Next Fragment");
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
FragmentTransaction fragmentTransaction = getFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.frameLayout, LastFragment.newInstance());
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
}
});
}
#Override
public void onDestroy() {
super.onDestroy();
Log.e("TAB", "onDestroy");
}
public static Fragment newInstance(int index) {
Bundle args = new Bundle();
args.putInt("tab_index", index);
TabFragment tab = new TabFragment();
tab.setArguments(args);
return tab;
}
}
LastFragment:
public class LastFragment extends Fragment {
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_last, container, false);
}
#Override
public void onViewCreated(View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
view.findViewById(R.id.button).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
getFragmentManager().popBackStack();
}
});
}
public static Fragment newInstance() {
return new LastFragment();
}
}

You have to Use getChildFragmentManager() For Viewpager to adapt Popback Feature.
VPAdapter adapter = new VPAdapter(getChildFragmentManager());
You Can Refer this Documentation on ChildFragmentManager()

After two different fragments have been replaced, first fragment is recreated when on pressed back button

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();

remove fragment on a button touch

I just need to remove a fragment when a button in it is tapped
public static class EditNameDialog extends DialogFragment {
...
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_find_in_page, container);
...
Button cancelButton = (Button) view.findViewById(R.id.cancel_button);
cancelButton.setOnTouchListener(new View.OnTouchListener()
{
public boolean onTouch(View arg0, MotionEvent arg1) {
//remove the fragment here
return false;
}
});
return view;
}
#Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
...
}
}
I just need to remove the fragment when the button is tapped

You can remove the fragment with use below code:
//remove the fragment from transaction manager
FragmentManager frgManager = getSupportFragmentManager();
Fragment fragment = frgManager.findFragmentByTag(tagName);
if (fragment != null) {
FragmentTransaction ft = frgManager.beginTransaction();
ft.remove(fragment).commit();
}

Wrong fragment is loading when I am trying to load new one

When I am trying to load a new fragment it loads previous fragment.
I have a fragment profile fragment and on it some onclicks are there. I want to open a new fragment on the click event but it is opening the previous fragment, somewhere backstack is missing or something else i could not find out.
relativeLayoutManagement.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
FragmentTransaction transaction;
if(getParentFragment() == null){
transaction = childFragmentManager.beginTransaction();
}else {
transaction = childFragmentManagerOfParent.beginTransaction();
transaction.replace(R.id.frameLayoutChildContainer, HotelManagementFragment.newInstance(),FragmentTags.HOTEL_MANAGEMENT);
transaction.addToBackStack(FragmentTags.HOTEL_MANAGEMENT);
transaction.commit();
}
}
});
}
This is my new fragment code.
public class HotelManagementFragment extends BaseFragment {
public HotelManagementFragment() {
}
public static HotelManagementFragment newInstance() {
HotelManagementFragment fragment = new HotelManagementFragment();
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_hotel_managment, container, false);
return view;
}
#Override
public void onViewCreated(View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
}
#Override
public void onDestroyView() {
super.onDestroyView();
}
}

If you are trying to load fragment on another fragment then Use that id which is in your main activity layout like this. //transaction.replace(R.id.main_activity_fragment_id,your_fragment);