Question

我有android应用程序。申请minSDK：15

我有NavigationDrawer。单击第一个导航抽屉菜单项时，我的新片段显示为MainFragment。一切都很好，就像在android教程中一样。

现在在这个片段中我需要实现简单的ViewPager。 ViewPager将页面碎片。

这是代码：

public class MainFragent extends Fragment
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        return inflater.inflate(R.layout.main_fragment_layout, container, false);
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);

        ArrayList<Books> books;
        BooksPageAdapter contentPageAdapter = new BooksPageAdapter(getFragmentManager(), books);
        ViewPager pager = (ViewPager) getActivity().findViewById(R.id.viewPager);
        pager.setAdapter(contentPageAdapter);
    }

    private class BooksPageAdapter extends FragmentStatePagerAdapter {
        private ArrayList<Books> books;

        public BooksPageAdapter(FragmentManager fm, private ArrayList<Books> books) {
            super(fm);

            this.books = books;
        }

        @Override
        public Fragment getItem(int pos) {
            return BooksFragment.newInstance(books);
        }

        @Override
        public int getCount() {
            return 5;
        }
    } }

和BooksFragment：

public class BooksFragment extends Fragment {
    private ArrayList<Books> books;

    static ContentFragment newInstance(final ArrayList<Books> books) {
        BooksFragment booksFragment = new BooksFragment();
        Bundle args = new Bundle();
        args.putSerializable("books", books);
        contentFragment.setArguments(args);
        return booksFragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        books = (ArrayList<Books>) getArguments().getSerializable(“books”);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_books, container, false);
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
    }

    @Override
    public void onResume() {
        super.onResume();

        updateUI(books);
    }

    public void updateUI(ArrayList<Books> books) {
        ListView listView = (ListView)getActivity().findViewById(R.id.list_view);
        listView.setAdapter(new MyArrayAdapter(getActivity(), books));
    }

    private class MyArrayAdapter extends ArrayAdapter<Books> {

        public MyArrayAdapter(final Context context, final List<Books> list) {
            super(context, R.layout.books_menu_item, R.id.title, list);
        }

        @Override
        public View getView(final int position,
                            final View convertView,
                            final ViewGroup parent) {
            final View row = super.getView(position, convertView, parent);
    Book book = getItem(position);
    textView.setText(book.getTitle());
            return row;
        }
    }
}

FirstPage看起来很棒，就像它应该的那样。我看到书名列表。但在第二页上，列表视图为空。除了ListView之外，第二页上的所有其他视图（如TextView ..）都很好。我做错了什么？

P.S FragmentStatePageAdapter来自support13。片段来自android包，而不是来自support4

Android：FragmentStatePageAdapter不更新ListView

0 个答案: