How to pass a String from an activity to fragment of a tabbed activity in android

Question

Before asking i have been through the similar questions and tried them but no success and every time it all ends with a null pointer exception. All i want to do is pass the username which is in string from one activity to another fragment of my tabbed activity. Here is what i tried, my main activity codes

Bundle bundle = new Bundle();
                bundle.putString("NAME", username);
                //PASS OVER THE BUNDLE TO OUR FRAGMENT
                ProfileFragment profileFragment = new ProfileFragment();
                profileFragment.setArguments(bundle);

                startActivity(new Intent(MainActivity.this, TabbedAct.class));

And codes from ProfileFragment

 @Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    View rootView = inflater.inflate(R.layout.fragment_profile, container, false);

    profilename = (TextView) rootView.findViewById(R.id.profile);

    String name= this.getArguments().getString("NAME");

    profilename.setText(name);

    return rootView;
}

Answer 1

it is because ProfileFragment is not visible yet. You are starting an Activity not fragment.

First, you need to intent the TabbedAct with extra value

Intent intent = new Intent(MainActivity.this, TabbedAct.class);
intent.putExtra("Name", username);
startActivity(intent);

Then, in TabbedAct Activity, you need to init your ProfileFragment

String username = getIntent().getStringExtra("Name");
ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());

.....
viewpager.setAdapter(viewPagerAdapter);
viewpager.setCurrentItem(0);
viewPagerAdapter.notifyDataSetChanged();

And codes from ProfileFragment

public static ProfileFragment newInstance(String username) {
    ProfileFragment f = new ProfileFragment();
    Bundle bdl = new Bundle();
    bdl.putString("NAME", username);
    f.setArguments(bdl);
    return f;
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    View rootView = inflater.inflate(R.layout.fragment_profile, container, false);

    profilename = (TextView) rootView.findViewById(R.id.profile);

    String name= this.getArguments().getString("NAME");

    profilename.setText(name);

    return rootView;
}

incase you don't have ViewPagerAdapter. You can use mine

viewPagerAdapter.addFragment(,);
viewPagerAdapter.addFragment(,"Tab2");
viewPagerAdapter.addFragment(Fragment2.newsIntance(),"Tab3");

public class ViewPagerAdapter extends FragmentPagerAdapter {
    private final String username;

    public ViewPagerAdapter(FragmentManager fragmentManager, String username) {
        super(fragmentManager);
        this.username = username;
    }

    @Override
    public Fragment getItem(int position) {
        if(position == 0) return ProfileFragment.newInstance(username);
        if(position == 1) return Fragment2.newsIntance();
        if(position == 2) return Fragment3.newsIntance();

        throw new IllegalStateException("Unexpected position " + position);
    }

    @Override
    public int getCount() {
        return 3;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        if(position == 0) return "Tab1";
        if(position == 1) return "Tab2";
        if(position == 2) return "Tab3";
      
        throw new IllegalStateException("Unexpected position " + position);
    }
}