In Fragment on back button pressed Activity is blank

Question

I have an Activity and many fragments inflated in same FrameLayout

Answer 1

On a recent personal project, I solved this by not calling addToBackStack if the stack is empty.

    // don't add the first fragment to the backstack
    // otherwise, pressing back on that fragment will result in a blank screen
    if (fragmentManager.getFragments() != null) {
        transaction.addToBackStack(tag);
    }

Here's my full implementation:

    String tag = String.valueOf(mCurrentSectionId);
    FragmentManager fragmentManager = mActivity.getSupportFragmentManager();
    Fragment fragment = fragmentManager.findFragmentByTag(tag);

    if (fragment != null) {
        // if the fragment exists then no need to create it, just pop back to it so
        // that repeatedly toggling between fragments doesn't create a giant stack
        fragmentManager.popBackStackImmediate(tag, 0);
    } else {
        // at this point, popping back to that fragment didn't happen
        // So create a new one and then show it
        fragment = createFragmentForSection(mCurrentSectionId);

        FragmentTransaction transaction = fragmentManager.beginTransaction()
                .setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN)
                .replace(R.id.main_content, fragment, tag);

        // don't add the first fragment to the backstack
        // otherwise, pressing back on that fragment will result in a blank screen
        if (fragmentManager.getFragments() != null) {
            transaction.addToBackStack(tag);
        }

        transaction.commit();
    }