Fragment re-created on bottom navigation view item selected

Question

Following is my code for bottom navigation view item selected

bottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {  
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {
    Fragment fragment = null;
    switch (item.getItemId()) {
        case R.id.action_one:
            // Switch to page one
            fragment = FragmentA.newInstance();
            break;
        case R.id.action_two:
            // Switch to page two
            fragment = FragmentB.newInstance();
            break;
        case R.id.action_three:
            // Switch to page three
            fragment = FragmentC.newInstance();
            break;
    }
    getSupportFragmentManager().beginTransaction().replace(R.id.container,fragment,"TAG").commit();
    return true;
}
});

Now my problem is every time fragment is re-created and don't want fragment to be recreated every time I also tried adding addToBackStack(null) but it this case on back button press keeps popping fragments from stack which I don't want.

Is there any way to display fragments on bottom navigation bar selected without re-creating fragment

To avoid that, I have create a map : Map<int, Fragment> and each fragment have a static id. I create all Fragment in onCreate of the Activity. But it's not recommended. You can add the fragment in the backstack with a unique tag like Fragment.class.getSimpleName(), then find it with findFragmentByTag and commit him again. Be sure to add each Fragment one time to the backstack — Raphael Teyssandier
– Raphael Teyssandier, Commented Feb 21, 2017 at 9:13
Hi Raphael as I said I don't want to add to it to backstack since it disturbs on back press implementation — amodkanthe
– amodkanthe, Commented Feb 21, 2017 at 9:15
For that you can Override onBackPressed() in your Activity. Comment super.onBackPressed() — Raphael Teyssandier
– Raphael Teyssandier, Commented Feb 21, 2017 at 9:17
no but there are some fragments other than these which will be added to stack if user performs action. I just don't want to add fragments associated with bottom navvigation view to backstack at same time dont want to recreate them — amodkanthe
– amodkanthe, Commented Feb 21, 2017 at 9:20
no click on bottom navigation bar items see it does not creates fragments again and again — amodkanthe
– amodkanthe, Commented Feb 21, 2017 at 10:26

Viven · Accepted Answer · 2018-06-12 06:01:02Z

26

With support library v26 you can do this

FragmentTransaction fragmentTransaction = mFragmentManager.beginTransaction();

Fragment curFrag = mFragmentManager.getPrimaryNavigationFragment();
if (curFrag != null) {
    fragmentTransaction.detach(curFrag);
}

Fragment fragment = mFragmentManager.findFragmentByTag(tag);
if (fragment == null) {
    fragment = new YourFragment();
    fragmentTransaction.add(container.getId(), fragment, tag);
} else {
    fragmentTransaction.attach(fragment);
}

fragmentTransaction.setPrimaryNavigationFragment(fragment);
fragmentTransaction.setReorderingAllowed(true);
fragmentTransaction.commitNowAllowingStateLoss();

edited Jun 12, 2018 at 6:01

answered Jul 25, 2017 at 10:48

Viven

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9 Comments

Viven Over a year ago

For a complete example you can look at this git repo github.com/okaybroda/FragmentStateManager

Burkely91 Over a year ago

Would you say this is the best way to handle navigation between three destinations when you want to keep the state/list positions etc when moving back and forth? Are there any caveats to using this method? Possible memory leaks or anything to be aware of? I'm not 100% sound on lifecycle quite yet

Burkely91 Over a year ago

Would it be better to do this or somehow restore instance state is what I really want to know I think!

Damn Vegetables Over a year ago

It did not seem to hold fragments in memory; it just somehow made page fragments look layered (page1 looked through below page2).

osrl Over a year ago

using show hide instead of attach detach works better. It won't restart fragment's lifecycle

|

Mazen Jameel · Accepted Answer · 2018-09-06 22:56:58Z

16

I faced the same problem and finally i i found the solution, you can try this code. it's work for me.

import android.support.annotation.NonNull;
import android.support.design.widget.BottomNavigationView;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.MenuItem;
import android.widget.FrameLayout;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
public BottomNavigationView bv;
public home_fragment home;
public account_fragment afrag;
public other_fragment other;
public FrameLayout fr;
android.support.v4.app.Fragment current;
//public FragmentTransaction frt;
    public static int temp=0;
    final Fragment fragment11 = new account_fragment();
    final Fragment fragment22 = new home_fragment();
    final Fragment fragment33 = new other_fragment();
    final FragmentManager fm = getSupportFragmentManager();
    Fragment active = fragment11;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        bv=(BottomNavigationView) findViewById(R.id.navigationView);


        fm.beginTransaction().add(R.id.main_frame, fragment33, "3").hide(fragment33).commit();
        fm.beginTransaction().add(R.id.main_frame, fragment22, "2").hide(fragment22).commit();
        fm.beginTransaction().add(R.id.main_frame,fragment11, "1").commit();
bv.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {

            @Override
            public boolean onNavigationItemSelected(@NonNull MenuItem item) {
                switch (item.getItemId()) {
                    case R.id.account:
                        fm.beginTransaction().hide(active).show(fragment11).commit();
                        active = fragment11;
                        return true;

                    case R.id.home1:
                        fm.beginTransaction().hide(active).show(fragment22).commit();
                        active = fragment22;
                        return true;

                    case R.id.other:
                        fm.beginTransaction().hide(active).show(fragment33).commit();
                        active = fragment33;
                        return true;
                }
                return false;
            }
        });
      bv.setOnNavigationItemReselectedListener(new BottomNavigationView.OnNavigationItemReselectedListener() {
          @Override
          public void onNavigationItemReselected(@NonNull MenuItem item) {
              Toast.makeText(MainActivity.this, "Reselected", Toast.LENGTH_SHORT).show();

          }
      });


    }

}

answered Sep 6, 2018 at 22:56

Mazen Jameel

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4 Comments

Gourav Khunger Over a year ago

Hat's off to you man! Really appreciate your work. You made my day. Thank you!

Gary Allen Over a year ago

Definitely the cleanest solution I think. And it's flexible - if you need to recreate the fragment, you just re-assign the relevant fragment variable. Thanks a lot!

Laura Galera Over a year ago

But this solution is not scalable. You will have to modify your code every time you want to add a new fragment.

Uzair Mughal Over a year ago

with this code navigation between specified fragments is flawless but we have to handle many other things if using nav components

Hejazi · Accepted Answer · 2019-10-23 12:20:59Z

This seemed to work well for me. Instead of attaching and detaching, i use show or hide to maintain fragment state.

    public void changeFragment(Fragment fragment, String tagFragmentName) {

        FragmentManager mFragmentManager = getSupportFragmentManager();
        FragmentTransaction fragmentTransaction = mFragmentManager.beginTransaction();

        Fragment currentFragment = mFragmentManager.getPrimaryNavigationFragment();
        if (currentFragment != null) {
            fragmentTransaction.hide(currentFragment);
        }

        Fragment fragmentTemp = mFragmentManager.findFragmentByTag(tagFragmentName);
        if (fragmentTemp == null) {
            fragmentTemp = fragment;
            fragmentTransaction.add(R.id.frame_layout, fragmentTemp, tagFragmentName);
        } else {
            fragmentTransaction.show(fragmentTemp);
        }

        fragmentTransaction.setPrimaryNavigationFragment(fragmentTemp);
        fragmentTransaction.setReorderingAllowed(true);
        fragmentTransaction.commitNowAllowingStateLoss();
    }

And this is how i use it

     private void initViews() {
        BottomNavigationView bottomNavigationView = findViewById(R.id.navigation);
        bottomNavigationView.setOnNavigationItemSelectedListener
                (new BottomNavigationView.OnNavigationItemSelectedListener() {
                    @Override
                    public boolean onNavigationItemSelected(@NonNull MenuItem item) {
                        Fragment selectedFragment = null;
                        switch (item.getItemId()) {
                            case R.id.explore:
                                changeFragment(new ExploreFragment(), ExploreFragment.class
                                        .getSimpleName());
                                toggleViews(true, "");
                                break;
                            case R.id.favorite:
                                changeFragment(new FavoriteFragment(), FavoriteFragment.class
                                        .getSimpleName());
                                toggleViews(false, "Favorites");
                                break;
                            case R.id.venue:
                                changeFragment(new VenueFragment(), VenueFragment.class.getSimpleName());
                                toggleViews(false, "Venues");
                                break;
                            case R.id.profile:
                                changeFragment(new ProfileFragment(), ProfileFragment.class
                                        .getSimpleName());
                                toggleViews(false, "Profile");
                                break;
                        }
                        return true;
                    }
                });

        //Manually displaying the first fragment - one time only
        changeFragment(new ExploreFragment(), ExploreFragment.class
                .getSimpleName());

    }

tronman · Accepted Answer · 2021-05-13 13:39:55Z

12

This solution stops a fragment from being re-created when the currently selected nav button is clicked again. However, a new fragment will be created every time the user clicks a different nav button.

Just add this line to avoid re-created Fragment from BottomNavigationView

 bottomNavigation.setOnNavigationItemReselectedListener(new BottomNavigationView.OnNavigationItemReselectedListener() {
            @Override
            public void onNavigationItemReselected(@NonNull MenuItem item) {
             // do nothing here   
            }
        });

Or with a lambda:

bottomNavigation.setOnNavigationItemReselectedListener(item -> { });

edited May 13, 2021 at 13:39

tronman

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answered Mar 2, 2020 at 6:42

Nikunj Paradva

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3 Comments

Dilip Hirapara Over a year ago

And you are real hero! you are life sever!

Nikunj Paradva Over a year ago

@DilipHirapara Dhanyawad mitra.. :D

Asad Over a year ago

setOnNavigationItemReselectedListener is deprecated, change to setOnItemReselectedListener

Maxwell · Accepted Answer · 2020-04-20 15:22:59Z

8

Be careful when using replace. Even if providing a fragment that already exists in memory, replace will restart the fragment's lifecycle. To avoid a restart, the transaction object's methods includes add, show, and hide, which can be used to show the correct fragment without restarting it.

private fun switchFragment(selectedTabIndex: Int) {
    val previousTabIndex = this.currentTabIndex
    this.currentTabIndex = selectedTabIndex

    val transaction = supportFragmentManager.beginTransaction()
    val tag = fragments[this.currentTabIndex].tag

    // if the fragment has not yet been added to the container, add it first
    if (supportFragmentManager.findFragmentByTag(tag) == null) {
        transaction.add(R.id.container, fragments[this.currentTabIndex], tag)
    }

    transaction.hide(fragments[previousTabIndex])
    transaction.show(fragments[this.currentTabIndex])
    transaction.commit()
}

edited Apr 20, 2020 at 15:22

answered Aug 9, 2017 at 15:35

Maxwell

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4 Comments

Burkely91 Over a year ago

You used slightly confusing wording there, just to clarify: replace doesn't restart a fragments's life cycle as it is added to the UI - it ends the fragment currently attached then adds the new frag, which we can only assume was previously destroyed if removed or it's being added for the first time. So it will surely be starting over yes but not because replace is forcing it to. Essentially replace = remove(oldFrag) then add(newFrag).

Damn Vegetables Over a year ago

What is currentTabPosition? android.support.design.widget.BottomNavigationView does not seem to have that property.

sandpat Over a year ago

One should be very careful while using findFragmentByTag ... it's better to avoid it altogether :P

shivamDev31 Over a year ago

@Maxwell can you clarify the above comments please? What is the index and currentTabPosition and what if this switchFragment method is in BaseActivity. Can you post an example with small activity or git gist. Thanks as this answer seems to be incomplete.

Raphael Teyssandier · Accepted Answer · 2017-02-21 10:35:54Z

7

Try this :

bottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
                @Override
                public boolean onNavigationItemSelected(@NonNull MenuItem item) {
                    Fragment fragment = null;
                    Fragment currentFragment = getSupportFragmentManager().findFragmentById(R.id.container);
                    switch (item.getItemId()) {
                        case R.id.action_one:
                            // Switch to page one
                            if (!(currentFragment instanceof FragmentA)) {
                                fragment = FragmentA.newInstance();
                            }
                            break;
                        case R.id.action_two:
                            // Switch to page two
                            if (!(currentFragment instanceof FragmentB)) {
                                fragment = FragmentB.newInstance();
                            }
                            break;
                        case R.id.action_three:
                            // Switch to page three
                            if (!(currentFragment instanceof FragmentC)) {
                                fragment = FragmentC.newInstance();
                            }
                            break;
                    }
                    getSupportFragmentManager().beginTransaction().replace(R.id.container, fragment, "TAG").commit();
                    return true;
                }
            });

That will get the current fragment in your container and if you click again on this fragment that will not re add the fragment.

answered Feb 21, 2017 at 10:35

Raphael Teyssandier

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6 Comments

Gowthaman M Over a year ago

How i can redirect to home page when i click on back button...please help me sir

Raphael Teyssandier Over a year ago

You can Override the fucntion onBackPressed on your main Activity.

Mitesh Vanaliya Over a year ago

In your code, If first FragmentA loaded, After click on second than second fragment loaded, after that If user click on firstFragment then is also recreate.

Raphael Teyssandier Over a year ago

@MiteshVanaliya Yes, if you want to not recreate every time the fragment, store the variable, or put all the fragment inside a ViewPagerand change the current item.

vinay Over a year ago

@Raphael Teyssandier current fragment returning null

|

akaMahesh · Accepted Answer · 2017-06-02 10:44:23Z

7

setOnNavigationItemReselectedListener would be a better solution for that

answered Jun 2, 2017 at 10:44

akaMahesh

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1 Comment

Odai A. Ali Over a year ago

I do agree with you

Zack · Accepted Answer · 2019-12-20 11:45:50Z

The best way i found to do it.

private void replace_fragment(Fragment fragment) {

        String tag = fragment.getClass().getSimpleName();
        FragmentTransaction tr = getSupportFragmentManager().beginTransaction();

        Fragment curFrag = getSupportFragmentManager().getPrimaryNavigationFragment();
        Fragment cacheFrag = getSupportFragmentManager().findFragmentByTag(tag);

        if (curFrag != null)
            tr.hide(curFrag);

        if (cacheFrag == null) {
            tr.add(R.id.main_frame, fragment, tag);
        } else {
            tr.show(cacheFrag);
            fragment = cacheFrag;
        }

        tr.setPrimaryNavigationFragment(fragment);
        tr.commit();

    }

private BottomNavigationView.OnNavigationItemSelectedListener mOnNavigationItemSelectedListener
            = new BottomNavigationView.OnNavigationItemSelectedListener() {

        @Override
        public boolean onNavigationItemSelected(@NonNull MenuItem item) {

            switch (item.getItemId()) {
                case R.id.nav_posts:
                    replace_fragment(new PostsFragment());
                    return true;
                case R.id.nav_stores:
                    replace_fragment(new StoresFragment());
                    return true;
                case R.id.nav_chats:
                    replace_fragment(new DiscussionsFragment());
                    return true;
                case R.id.nav_account:
                    replace_fragment(new ProfileFragment());
                    return true;
            }
            return false;
        }
    };

Pang · Accepted Answer · 2017-12-04 04:31:36Z

3

Use setOnNavigationItemReselectedListener like this:

private BottomNavigationView.OnNavigationItemReselectedListener onNavigationItemReselectedListener
            = new BottomNavigationView.OnNavigationItemReselectedListener() {

        @Override
        public void onNavigationItemReselected(@NonNull MenuItem item) {
            Toast.makeText(MainActivity.this, "Reselected", Toast.LENGTH_SHORT).show();
        }
    };

and call it using:

navigation.setOnNavigationItemReselectedListener(onNavigationItemReselectedListener);

edited Dec 4, 2017 at 4:31

Pang

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answered Dec 3, 2017 at 16:55

Akshay Sahai

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5 Comments

Timuçin Over a year ago

How does this answer the question?

Akshay Sahai Over a year ago

@Timuçin whatever you perform inside this function, it will be performed on item reselect, so if you do not wish to create a new fragment then leave it empty.

Harminder Singh Over a year ago

Not even going inside the reselect function.

couceirof Over a year ago

@Timuçin when the reselect listener is set, the normal one won't be fired on item reselection.

Eaweb Over a year ago

In 2019, item reselection is only triggered when you select the current item on are on again. Probably useful for something like scroll to top if the current fragment houses a vertical list.

osrl · Accepted Answer · 2018-09-22 17:48:41Z

I've improved @Viven's answers and written it with Kotlin. My version instantiates fragment only for the first time, hides/shows. I'm new at Kotlin so tell me if I can improve anything.

We need to hold a id to tag map:

private val fragmentTags = hashMapOf(
        R.id.action_home to "home_fragment",
        R.id.action_profile to "profile_fragment"
)

The listener code:

bottomNavigation.run {
    setOnNavigationItemSelectedListener { menuItem ->
        supportFragmentManager.beginTransaction()
                .let { transaction ->
                    // hide current fragment
                    supportFragmentManager.primaryNavigationFragment?.let {
                        // if selected fragment's tag is same, do nothing.
                        if (it.tag == fragmentTags[menuItem.itemId]) {
                            return@setOnNavigationItemSelectedListener true
                        }

                        transaction.hide(it)
                    }

                    var fragment  = supportFragmentManager.findFragmentByTag(fragmentTags[menuItem.itemId])

                    if (fragment == null) {
                        // instantiate fragment for the first time
                        fragment = when(menuItem.itemId) {
                            R.id.action_home -> HomeFragment()
                            R.id.action_profile -> ProfileFragment()
                            else -> null
                        }?.also {
                            // and add it 
                            transaction.add(R.id.frame, it, fragmentTags[menuItem.itemId])
                        }
                    } else {
                        // if it's found show it 
                        transaction.show(fragment)
                    }


                    transaction
                            .setPrimaryNavigationFragment(fragment)
                            .setReorderingAllowed(true)
                }.commitNowAllowingStateLoss()

        return@setOnNavigationItemSelectedListener true
    }

    //bottomNavigation things
    itemIconTintList = null
    selectedItemId = R.id.action_home
}

ivan8m8 · Accepted Answer · 2018-11-07 14:11:35Z

I solved this problem by adding a ViewPager to which I delegated all my navigation fragments. Its adapter (FragmentPagerAdapter) doesn't recreate the fragments instances when the user navigates through the BotoomNavigationView.

To achieve this, you have to complete 5 easy steps:

add a ViewPager to your layout;

implement its adapter:

class YourNavigationViewPagerAdapter(fm: FragmentManager,
                                     private val param1: Int,
                                     private val param2: Int)

    : FragmentPagerAdapter(fm) {

    override fun getItem(p0: Int) = when(p0) {
        0 -> NavigationFragment1.newInstance(param1, param2)
        1 -> NavigationFragment2.newInstance(param1, param2)
        2 -> NavigationFragment3.newInstance(param1, param2)
        else -> null
    }

    override fun getCount() = 3
}

don't forget to set the new adapter:

yourViewPager.adapter = YourNavigationViewPagerAdapter(supportFragmentManager, param1, param2)

set a OnNavigationItemSelectedListener to your BottomNavigationView like the following:

yourBottomNavigationView.setOnNavigationItemSelectedListener {

    when(it.itemId) {

        R.id.yourFirstFragmentMenuItem -> {
            yourViewPager.currentItem = 0
            true
        }

        R.id.yourSecondFragmentMenuItem -> {
            yourViewPager.currentItem = 1
            true
        }

        R.id.yourThirdFragmentMenuItem -> {
            yourViewPager.currentItem = 2
            true
        }


        else -> false
    }
}

set a OnPageChangeListener to your ViewPager like the following:

yourViewPager.addOnPageChangeListener(object : 
ViewPager.OnPageChangeListener {
    override fun onPageScrollStateChanged(p0: Int) {

    }

    override fun onPageScrolled(p0: Int, p1: Float, p2: Int) {

    }

    override fun onPageSelected(p0: Int) {
        yourBottomNavigationView.menu.getItem(p0).isChecked = true
    }

})

enjoy :)

Sharukh Mohammed · Accepted Answer · 2019-05-14 06:05:48Z

1

I wrote an Extension function in Kotlin for the same.

fun FragmentManager.switch(containerId: Int, newFrag: Fragment, tag: String) {

var current = findFragmentByTag(tag)
beginTransaction()
    .apply {

        //Hide the current fragment
        primaryNavigationFragment?.let { hide(it) }

        //Check if current fragment exists in fragmentManager
        if (current == null) {
            current = newFrag
            add(containerId, current!!, tag)
        } else {
            show(current!!)
        }
    }
    .setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN)
    .setPrimaryNavigationFragment(current)
    .setReorderingAllowed(true)
    .commitNowAllowingStateLoss()
}

answered May 14, 2019 at 6:05

Sharukh Mohammed

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Comments

HarshitG · Accepted Answer · 2018-06-06 06:34:08Z

There are several test cases involved in proper navigation , I am pasting my code with all test cases checked.

FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
        switch (item.getItemId()) {
            case R.id.dashboard:
                Fragment fragment;
                fragment = fragmentManager.findFragmentByTag(DashboardFragment.TAG);

                if (fragment == null) {
                    fragment = new DashboardFragment();
                    fragmentTransaction.add(R.id.frame, fragment, DashboardFragment.TAG);
                } else {
                    fragmentTransaction.detach(fragmentManager.getPrimaryNavigationFragment());
                    fragmentTransaction.attach(fragment);
                }
                fragmentTransaction.setPrimaryNavigationFragment(fragment);
                fragmentTransaction.commitNow();
                return true;
            case R.id.expenses:
                fragment = fragmentManager.findFragmentByTag(ExpenseFragment.TAG);
                if (fragment == null) {
                    fragment = new ExpenseFragment();
                    fragmentTransaction.add(R.id.frame, fragment, ExpenseFragment.TAG);
                } else {
                    fragmentTransaction.detach(fragmentManager.getPrimaryNavigationFragment());
                    fragmentTransaction.attach(fragment);
                }
                fragmentTransaction.setPrimaryNavigationFragment(fragment);
                fragmentTransaction.commitNow();
                return true;
            case R.id.vehicle_parts:
                Bundle bundle = new Bundle();
                bundle.putInt("odometer", vehicle.getOdometer());
                bundle.putString("vehicle_id", vehicle.get_id());
                fragment = fragmentManager.findFragmentByTag(PartsFragment.TAG);
                if (fragment == null) {
                    fragment = new PartsFragment();
                    fragment.setArguments(bundle);
                    fragmentTransaction.add(R.id.frame, fragment, PartsFragment.TAG);

                } else {
                    fragmentTransaction.detach(fragmentManager.getPrimaryNavigationFragment());
                    fragmentTransaction.attach(fragment);
                }
                fragmentTransaction.setPrimaryNavigationFragment(fragment);
                fragmentTransaction.commitNow();
                return true;
            case R.id.blog:
                fragment = fragmentManager.findFragmentByTag(BlogFragment.TAG);

                if (fragment == null) {
                    fragment = new BlogFragment();
                    fragmentTransaction.add(R.id.frame, fragment, BlogFragment.TAG);

                } else {
                    fragmentTransaction.detach(fragmentManager.getPrimaryNavigationFragment());
                    fragmentTransaction.attach(fragment);
                }
                fragmentTransaction.setPrimaryNavigationFragment(fragment);
                fragmentTransaction.commitNow();
                return true;
        }
        return false;

Davud Davudov · Accepted Answer · 2019-11-08 05:52:27Z

0

Use Cicerone library for handling navigation easily.

https://github.com/terrakok/Cicerone

@Override
public boolean onNavigationItemSelected(@NonNull MenuItem menuItem) {
    switch (menuItem.getItemId()) {
        case R.id.save: {
            router.replaceScreen("your fragment1");
            menuItem.setChecked(true);
            break;
        }
        case R.id.search_lessons: {
            router.replaceScreen("your fragment2");
            menuItem.setChecked(true);
            break;
        }
        case R.id.profile_student: {
            router.replaceScreen("your fragment3");
            menuItem.setChecked(true);
            break;
        }

    }
    return false;
}

answered Nov 8, 2019 at 5:52

Davud Davudov

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Comments

Sunil Chaudhary · Accepted Answer · 2020-09-07 10:26:07Z

How To stop recreating Fragment when it is Already Visible Using BottomNavigationView

Step 1--

     @Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {
    Fragment fragment = null;
    String valuestring;      
    **if (item.getItemId() == lastSelectedItemId) { // added this
        Log.e( "both id is same","LULL" );
        return true;
    }**
    switch (item.getItemId()) {
       case R.id.navigation_category:
      SetActioBarText( getString( R.string.label_actionbar_categories ) );
            fragment = new CategoryFragment();
            valuestring = "category";
            break;
        case R.id.navigation_favourite:
     SetActioBarText( getString( R.string.label_actionbar_favourites ) );
            fragment = new FavouriteFragment();
            valuestring = "favourites";
            break;
        default:
            throw new IllegalStateException( "Unexpected value: " +                  menuItem.getItemId() );
    }
    return loadFragment( fragment, valuestring ,menuItem);
}

Now Step 2---

    private boolean loadFragment(Fragment fragment, String argument,MenuItem item) {
  
    if (fragment != null) {
       
        transaction = fragmentManager.beginTransaction();
        transaction.addToBackStack( argument );
        transaction.setTransition( FragmentTransaction.TRANSIT_FRAGMENT_FADE );
        transaction.replace( R.id.frame_container, fragment,                         "demofragment").commitAllowingStateLoss();

     lastSelectedItemId= item.getItemId();
    
        return true;
    }
    return false;
}

Mohamad Alemi · Accepted Answer · 2021-03-15 07:15:23Z

-1

no need to do this answers. actually what you really need is to save view in specific fragmet.

 private   View view;
if(view == null){
    view = inflater.inflate(R.layout.call_fragment_edited, container, false);

}

so any time when you create new fragment you see current state

edited Mar 15, 2021 at 7:15

answered Dec 13, 2020 at 8:55

Mohamad Alemi

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1 Comment

Chetan Gupta Over a year ago

We should never cache views especially on fragments

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