如何回到Android

Question

当我点击后退按钮时，我想回到我之前的片段。我在做什么不起作用。

片段替换的代码：

Fragment fragment=new MyFragment();
FragmentManager fragmentManager = getActivity().getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager
    .beginTransaction();
fragmentTransaction.setCustomAnimations(R.anim.slide_in,R.anim.slide_out);
fragmentTransaction.replace(R.id.container_body, fragment);
fragmentTransaction.commit();

后退按钮的抓取代码：

@Override
public void onResume() {
    super.onResume();
    getActivity().invalidateOptionsMenu();
    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) {
                getActivity().finish();
                getActivity().overridePendingTransition(R.anim.slide_enter, R.anim.slide_exit);
                return true;
            }
            return false;
        }
    });

我也试过

getActivity().getSupportFragmentManager().popBackStack();

Answer 1

像这样改变这个垫子帮助

Fragment fragment=new MyFragment();
               FragmentManager fragmentManager = getActivity().getSupportFragmentManager();
               FragmentTransaction fragmentTransaction = fragmentManager
                        .beginTransaction();
                fragmentTransaction.setCustomAnimations(R.anim.slide_in,R.anim.slide_out);
                fragmentTransaction.replace(R.id.container_body, fragment).addToBackStack(null);
                fragmentTransaction.commit();

如果有任何错误，请告诉我

Answer 2

你可以这样做。

   DetailsFragment detailsFragment = new DetailsFragment();
            Bundle bundle = new Bundle();
            bundle.putString("ID", Id);
                    detailsFragment.setArguments(bundle);

            FragmentTransaction transaction = getFragmentManager().beginTransaction();
            transaction.add(R.id.detail_container, detailsFragment);
            transaction.addToBackStack(this.getClass().getSimpleName());
            transaction.hide(DetailsFragment.this);
            transaction.commit();