android change default item in bottom bar

Question

I use bottom bar in my application .but I want to change default item(tab) in bottom bar.I do not use any external library.just how I can set my favorite tab when application runs.

My codes:

BottomNavigationView 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.action_home:
                selectedFragment = Fragment1.newInstance();
                break;
            case R.id.action_product:
                selectedFragment = Fragment2.newInstance();
                break;
            case R.id.action_order:
                selectedFragment = Fragment3.newInstance();
                break;
            case R.id.action_contact:
                selectedFragment = Fragment4.newInstance();
                break;
        }

        FragmentManager fragmentManager = getSupportFragmentManager();
        FragmentTransaction transaction = fragmentManager.beginTransaction();
        transaction.replace(R.id.scrollView, selectedFragment);
        transaction.commit();
        return true;
    }

});

Rnld · Answer 1 · 2018-01-25T20:03:18.103

2

bottomNavigationView.setSelectedItemId(R.id.action_home);

This will work

edited Jan 25 '18 at 20:03

answered Jan 25 '18 at 18:35

Rnld

68
9

Is the bottom navigation bar a external library? – Rnld Jan 25 '18 at 18:53
Which one do you want to set as default? – Rnld Jan 25 '18 at 19:10
my app direction is right to left and I set support ltr false in manifest.now the last item from right(and the first item from left) is active and I want change it to first item from right. – Jan 25 '18 at 19:14
Which fragment do you want to set as the selected fragment? – Rnld Jan 25 '18 at 19:16
the fragment I want to set default is fragment 1 – Jan 25 '18 at 19:55
it works for api 25 and higher .how I can use for lower api? – Jan 25 '18 at 20:11

score 2 · Accepted Answer · answered Jan 25 '18 at 22:34

2

This should work (I use it with api 19+)

bottomNavigationView.getMenu().getItem(index).setChecked(true);

answered Jan 25 '18 at 22:34

pgentili

659
5
13

score 1 · Answer 3 · answered Jan 25 '18 at 20:38

1

    for (int i = 0, size = menu.size(); i < size; i++) {
        MenuItem item = menu.getItem(i);
        item.setChecked(item.getItemId() == 0);
    }

answered Jan 25 '18 at 20:38

score 0 · Answer 4 · answered Jan 25 '18 at 18:34

0

If you want a specific item to be opened when the app is started. Just try this code:

bottomNavigationView.setSelectedItemId(R.id.your_id);

But it is for API 25 and higher only.

answered Jan 25 '18 at 18:34

TREAF ALSHEMERI

409
5
12

how can I use for lower api? – Jan 25 '18 at 18:49

android change default item in bottom bar

4 Answers4