How to show fragment in android

Question

I am using ViewPager to create 3 Fragment on Activity1,
this is my viewPager adapter :

 public class ViewPagerAdapter extends FragmentStatePagerAdapter {
    int mNumOfTabs;

    public ViewPagerAdapter(FragmentManager fm, int NumOfTabs) {
        super(fm);
        this.mNumOfTabs = NumOfTabs;
    }

    @Override
    public Fragment getItem(int position) {

        switch (position) {
            case 0:
                Fragment1 tab1 = new Fragment1();
                return tab1;
            case 1:
                Fragment2 tab2 = new Fragment2();
                return tab2;
            case 2:
                Fragment3 tab3 = new Fragment3();
                return tab3;
            default:
                return null;
        }
    }

    @Override
    public int getCount() {
        return mNumOfTabs;
    }

}

this is Activity :

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_1);

    TabLayout tab_layout = (TabLayout) findViewById(R.id.tab_layout);
    tab_layout.addTab(tab_layout.newTab().setText("Frag1"));
    tab_layout.addTab(tab_layout.newTab().setText("Frag2"));
    tab_layout.addTab(tab_layout.newTab().setText("Frag3"));

    final ViewPager view_pager = (ViewPager) findViewById(R.id.viewpager);

    final ViewPagerAdapter adapter = new ViewPagerAdapter
            (getSupportFragmentManager(), tab_layout.getTabCount());

    view_pager.setAdapter(adapter);

    view_pager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tab_layout));

    tab_layout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {

        @Override
        public void onTabSelected(TabLayout.Tab tab) {
            view_pager.setCurrentItem(tab.getPosition());
        }

        @Override
        public void onTabUnselected(TabLayout.Tab tab) {
        }

        @Override
        public void onTabReselected(TabLayout.Tab tab) {
        }
    });

}

When Activity1 is open it show Fragment1 . But I want to show Fragment2 or Fragment3 instead .
How I can to do that?

score 2 · Accepted Answer · answered Jul 05 '16 at 03:07

2

Add this line after viewpager.setAdapter(adapter); :

viewPager.setCurrentItem(index);

Index is depending on you , how many fragments you have. tabLayout.getTabCount(); will return you tab count. But index is starting from 0.

If you have 3 Fragment and want to show third Fragment you must use viewPager.setCurrentItem(2);

answered Jul 05 '16 at 03:07

Yasin Kaçmaz

6,573
5
40
58

@1234abcd no problem , i think you got what is index ! – Yasin Kaçmaz Jul 05 '16 at 03:25

score 1 · Answer 2 · edited May 23 '17 at 11:51

1

Set current position of viewpager to your desired possition which is 2 or 3 in your case.

 new Handler().post(new Runnable() {
                @Override
                public void run() {
                    mViewPager.setCurrentItem(desiredPos);
                }
            });

seee more

Android ViewPager setCurrentItem not working after onResume

edited May 23 '17 at 11:51

Community

1
1

answered Jul 05 '16 at 03:14

Hitesh Sahu

41,955
17
205
154

How to show fragment in android

2 Answers2