Question

我试图让一个标签布局使用一个公共片段，它传递一个名为category的参数字符串，用于过滤要在活动中显示的查询，具体取决于标签位置。这是我的ClothingSectionsPagerAdapter类来处理这个问题。

public class ClothingSectionsPagerAdapter extends FragmentStatePagerAdapter {

    private String[] mCategories;

    public ClothingSectionsPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    public void setContext(Context context) {
        mCategories = context.getResources().getStringArray(R.array.category);
    }

    @Override
    public Fragment getItem(int position) {
        return ClothingCategoryFragment.newInstance(mCategories[position]);
    }

    @Override
    public int getCount() {
        return mCategories.length;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        return mCategories[position];
    }
}

传递字符串参数的片段应该在屏幕上加载此类别的服装项目。这是我的片段。

public class ClothingCategoryFragment extends Fragment {

    @BindView(R.id.catalog_swipe_refresh_layout)
    SwipeRefreshLayout mCatalogRefreshLayout;

    @BindView(R.id.catalog_recycler_view)
    RecyclerView mCatalogRecyclerView;

    private CatalogAdapter mCatalogAdapter;
    private List<Clothing> mClothing;
    private String mCategory;

    private ClothingRepositoryActions mCatalogRepository;

    public ClothingCategoryFragment() {
        // Required empty public constructor
    }

    public static ClothingCategoryFragment newInstance(String category) {
        ClothingCategoryFragment clothingCategoryFragment =
                new ClothingCategoryFragment();
        Bundle args = new Bundle();
        args.putString(CATEGORY_FRAGMENT_ARGUMENT_KEY, category);
        clothingCategoryFragment.setArguments(args);
        return clothingCategoryFragment;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View rootView = inflater.inflate(R.layout.fragment_clothing_category,
                container, false);
        ButterKnife.bind(this, rootView);

        setAdapter();

        mCatalogRepository = new ClothingRepository();
        mCategory = getArguments().getString(CATEGORY_FRAGMENT_ARGUMENT_KEY, mCategory);
        loadClothing();

        mCatalogRefreshLayout.setColorSchemeResources(R.color.refresh_progress_1);
        mCatalogRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
            @Override
            public void onRefresh() {
                loadClothing();
            }
        });

        return rootView;
    }

    // Irrelevent methods omitted
    ...

    public void setAdapter() {
        mClothing = new ArrayList<>();
        mCatalogRecyclerView.setHasFixedSize(true);
        mCatalogAdapter = new CatalogAdapter(getActivity(), mClothing);

        final GridLayoutManager layoutManager = new GridLayoutManager(getActivity(), 2);

        mCatalogRecyclerView.setLayoutManager(layoutManager);
        mCatalogRecyclerView.setAdapter(mCatalogAdapter);
    }

    public void loadClothing() {
        if (isNetworkAvailable()) {
            mCatalogRepository.loadClothing(mCategory);
        } else {
            mCatalogRepository.loadClothingFromRealm(mCategory);
        }
    }

    private boolean isNetworkAvailable() {
        ConnectivityManager connectivityManager
                = (ConnectivityManager) getActivity().getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
        return activeNetworkInfo != null && activeNetworkInfo.isConnected();
    }
}

当我在标签之间切换时，查询结果没有变化，这意味着不会调用loadClothing方法。我猜测片段已创建，onCreateView仅针对每个片段调用一次。但是，一旦我使用刷新布局刷新片段，就会显示正确的结果，这意味着正确的类别字符串用于查询。 我的问题是如何在切换标签时让片段使用正确的类别字符串调用loadClothing？

使用FragmentStatePagerAdapter在标签之间切换时如何更新片段？

0 个答案: