KeyEvent.KEYCODE_BACK在Fragment中被调用两次

Question

我在我的片段中调用了我的View上的KeyEvent.KEYCODE_BACK,并且由于一些奇怪的原因它被调用了两次.

我不知道它为什么会这样做.

这是我的片段:

    @Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    myFragmentView = inflater.inflate(R.layout.folders, container, false);

    myFragmentView.setFocusableInTouchMode(true);
    myFragmentView.requestFocus();
    myFragmentView.setOnKeyListener(new View.OnKeyListener() {

        @Override
        public boolean onKey(View v, int keyCode, KeyEvent event) {
            // TODO Auto-generated method stub

            if (keyCode == KeyEvent.KEYCODE_BACK) {

                String parent = file.getParent().toString();
                file = new File(parent);
                File list[] = file.listFiles();

                myList.clear();

                for (int i = 0; i < list.length; i++) {
                    myList.add(list[i].getName());
                }
                Toast.makeText(getActivity(), parent, Toast.LENGTH_LONG)
                        .show();
                setListAdapter(new ArrayAdapter<String>(getActivity(),
                        android.R.layout.simple_list_item_1, myList));

            }

            return true;

        }
    });

    return myFragmentView;
}

Answer 1

正确的是,onKey将被调用两次,一次用于Down事件,另一次用于Up事件.请尝试添加条件:

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

希望能帮助到你.