How go back from Fragment A to Fragment B?

Question

I need to go from FragmentA to FragmentB (i'm using navigationdrawer)

I create this method in FragmentB:

public void onBackPressed(){
    FragmentManager fm = getActivity().getFragmentManager();
    fm.popBackStackImmediate();
}

but they don't work, how can i implement this method?

Answer 1

When you add your fragment, you also have to add it to your fragment's backstack.

FragmentTransaction ft = getSupportFragmentManager.beginTransaction();
                  ft.replace(R.id.content, fragment, backStateName);
                  ft.addToBackStack(backStateName);
                  ft.commit();

(here R.id.content is your fragment container in your activity)

Then you have to override onBackPressed method in your activity that contains your fragments.

@Override
public void onBackPressed() {
 if (getSupportFragmentManager().getBackStackEntryCount() > 1) {
                 getSupportFragmentManager().popBackStack();
  }
}

if you want to customize your onBackPressed then you can check for your currently visible fragment in your activity and create a callback for performing action for that particular fragment. example -

    @Override
    public void onBackPressed() {
     if (getSupportFragmentManager().getBackStackEntryCount() > 1) {
              Fragment fragment = getSupportFragmentManager().findFragmentById(R.id.content);
              if (fragment instanceof FragmentB) {
                            ((FragmentB) fragment).onBackPressed();
//                     getSupportFragmentManager().popBackStack();
      }
    }

now you can add getSupportFragmentManager().popBackStack(); in your Fragment's onBackPressed() method.