Handling back press when using fragments in Android

Question

I am using Android Sliding Menu using Navigation Drawer in my application and Fragments are used in the app instead of Activities. When I open the drawer, click on an item a Fra

Answer 1

I usually set an onKeyListener to the View in onResume. From what I learned you have to take care to set setFocusableInTouchMode() and requestFocus on the View.

This is a sample of what I use for this purpose:

@Override
public void onResume() {

    super.onResume();

    getView().setFocusableInTouchMode(true);
    getView().requestFocus();
    getView().setOnKeyListener(new View.OnKeyListener() {
        @Override
        public boolean onKey(View v, int keyCode, KeyEvent event) {

            if (event.getAction() == KeyEvent.ACTION_UP && keyCode == KeyEvent.KEYCODE_BACK){

                // handle back button

                return true;

            }

            return false;
        }
    });
}

Answer 2

use this (in kotlin)

activity?.onBackPressedDispatcher?.addCallback(this, object : OnBackPressedCallback(true) {
    override fun handleOnBackPressed() {
        // in here you can do logic when backPress is clicked
    }
})

i think this is the most elegant way to do it

Answer 3

        view.setFocusableInTouchMode(true);
        view.requestFocus();
        view.setOnKeyListener(new View.OnKeyListener() {
        @Override
        public boolean onKey(View v, int keyCode, KeyEvent event)   {
        if (keyCode == KeyEvent.KEYCODE_BACK) {


            Fragment NameofFragment = new NameofFragment;

            FragmentTransaction  transaction=getFragmentManager().beginTransaction();
            transaction.replace(R.id.frame_container,NameofFragment);

            transaction.commit();

            return true;
        }
        return false;
    }
});

return view;

Answer 4

In your oncreateView() method you need to write this code and in KEYCODE_BACk condition you can write whatever the functionality you want

   View v = inflater.inflate(R.layout.xyz, container, false);
    //Back pressed Logic for fragment
    v.setFocusableInTouchMode(true);
    v.requestFocus();
    v.setOnKeyListener(new View.OnKeyListener() {
        @Override
        public boolean onKey(View v, int keyCode, KeyEvent event) {
            if (event.getAction() == KeyEvent.ACTION_DOWN) {
                if (keyCode == KeyEvent.KEYCODE_BACK) {
                    getActivity().finish();
                    Intent intent = new Intent(getActivity(), MainActivity.class);
                    startActivity(intent);

                    return true;
                }
            }
            return false;
        }
    });

Answer 5

Try these methods. To me, the most useful solution is as follows:

In MainActivity:

getSupportFragmentManager().beginTransaction().replace(R.id.gif_contents, gifPageTwoFragment, "gifPageTwoFragment").addToBackStack("gifPageTwoFragment").commit();

In GifPageTwoFragment:

@Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        getView().setFocusableInTouchMode(true);
        getView().requestFocus();
        getView().setOnKeyListener(new View.OnKeyListener() {
            @Override
            public boolean onKey(View v, int keyCode, KeyEvent event) {
                if (event.getAction() == KeyEvent.ACTION_UP && keyCode == KeyEvent.KEYCODE_BACK) {
                    Log.e("gif--","fragment back key is clicked");
                    getActivity().getSupportFragmentManager().popBackStack("gifPageTwoFragment", FragmentManager.POP_BACK_STACK_INCLUSIVE);
                    return true;
                }
                return false;
            }
        });
    }