Question

以下是我的应用的截图。

enter image description here

此屏幕是一个具有滑动标签布局的片段。它将包含另一个将在listview中显示数据的片段。问题是，为了加载数据，从微调器中选择的值需要在选项卡中的片段内传递。我不知道该怎么做。一种方法是选项卡片段实现回调，并且应该加载回调数据。但我没有得到如何在微调器的onItemSelected中注册该回调。

注意：选项卡中的所有片段仅在listview中显示数据，因此我创建了一个公共片段。

这是我的代码到目前为止： 截图的片段

public class BuyListingFragment2 extends BaseFragment {
private Context ctx;
private Spinner vehicle_type;
private ArrayList<ListingTabModel> mListingTabs = new ArrayList<ListingTabModel>();
private ArrayAdapter<String> spinnerAdapter;
private ArrayList<String> vehicleTypeSpinnerlist;
private int spinnerPosition;
private SlidingTabLayout sliding_tabs;
private BuyListingPagerAdapter buyListingPagerAdapter;

public static BuyListingFragment2 newInstance(String category,
        int position, String preselectedFilters) {
    BuyListingFragment2 fragment = new BuyListingFragment2();
    Bundle args = new Bundle();
    args.putString("vehicle_type", category);
    args.putInt("spinner_position", position);
    fragment.setArguments(args);
    return fragment;
}

public BuyListingFragment2() {

}   
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    this.vehicleType = getArguments().getString("vehicle_type");
    this.selectedVehicle = this.vehicleType;
    this.spinnerPosition = getArguments().getInt("spinner_position");

    ArrayList<CategoryType> vehicleTypeList = RegistrationResponse
            .getInstance().getVehicleTypeList();
    spinnerAdapter = new ArrayAdapter<String>(getActivity(),
            android.R.layout.simple_list_item_1, vehicleTypeList);
    buyListingPagerAdapter = new BuyListingPagerAdapter(
            getChildFragmentManager(), mListingTabs);
}

@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
    ctx = getActivity();
    vehicle_type = (Spinner) view.findViewById(R.id.vehicle_type);
    vehicle_type.setAdapter(spinnerAdapter);
    vehicle_type.setSelection(spinnerPosition, false);
    if (mListingTabs.isEmpty()) {
        String[] tabNames = getResources().getStringArray(
                R.array.listing_tab_names);
        for (int i = 0; i < tabNames.length; i++) {
            String tabName = tabNames[i];
            ListingTabModel mListingTabModel = new ListingTabModel();
            mListingTabModel.setTagName(tabName);
            mListingTabs.add(mListingTabModel);
        }
    }
    buyListingPagerAdapter.notifyDataSetChanged();
    listing_layout_viewpager = (ViewPager) view
            .findViewById(R.id.listing_layout_viewpager);
    listing_layout_viewpager.setAdapter(buyListingPagerAdapter);
    sliding_tabs = (SlidingTabLayout) view.findViewById(R.id.sliding_tabs);
    sliding_tabs.setDistributeEvenly(true);
    sliding_tabs.setViewPager(listing_layout_viewpager);
    vehicle_type.setOnItemSelectedListener(new OnItemSelectedListener() {

        @Override
        public void onItemSelected(AdapterView<?> parent, View view,
                int position, long id) {
            spinnerPosition = position;
            //How to register listener here
        }

        @Override
        public void onNothingSelected(AdapterView<?> parent) {

        }
    });
}   
}

标签内的常见片段

public class ListingFragment extends BaseFragment implements
    OnSpinnerDataSelected {
private InfiniteListView mListView;
private BuyListingListAdapter buyListingAadapter;
private RobotoLightTextView emptyMessage;
private int currentPageNumber = 1;
private int totalPages;
private HashMap<String, String> params = new HashMap<String, String>();
private int apiCallCount = 0;
private Context ctx;
private String vehicleType;
private ProgressBar progressBar;
public ListingFragment() {
}

public static ListingFragment newInstance(ListingTabModel mListingTabModel) {
    ListingFragment mFragment = new ListingFragment();
    Bundle bundle = new Bundle();
    // bundle.putBoolean("is_grid_view", mListingTabModel.isShowGridView());
    // bundle.putString("vehicle_type", mListingTabModel.getVehicleType());
    mFragment.setArguments(bundle);
    return mFragment;
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
    ctx = getActivity();
    emptyMessage = (RobotoLightTextView) view
            .findViewById(R.id.empty_message);
    mListView = (InfiniteListView) view.findViewById(R.id.lstVw_buy);

    boolean isGrid = getArguments().getBoolean("is_grid_view");

    vehicleType = getArguments().getString("vehicle_type");

    buyListingAadapter = new BuyListingListAdapter(ctx,
            mVehicleListingList, isGrid);
    mListView.setAdapter(buyListingAadapter);
    progressBar = new ProgressBar(ctx);
}

@Override
public int getLayoutId() {
    return R.layout.layout_messages;
}
@Override
public void onSpinnerDataSelected(String vehicleCategory) {
    // TODO: fetch listing data
}
}

由ListingFragment实施的回调

public interface OnSpinnerDataSelected {
        void onSpinnerDataSelected(String vehicleCategory);
}

FragmentStatePagerAdapter

public class BuyListingPagerAdapter extends FragmentStatePagerAdapter {

    ArrayList<ListingTabModel> mFragmentsList;

    public BuyListingPagerAdapter(FragmentManager fm,
            ArrayList<ListingTabModel> mFragmentsList) {
        super(fm);
        this.mFragmentsList = mFragmentsList;
    }

    @Override
    public Fragment getItem(int index) {
        ListingFragment listingFragment = ListingFragment
                .newInstance(mFragmentsList.get(index));
        return listingFragment;
    }

    @Override
    public int getCount() {
        return mFragmentsList.size();
    }

    @Override
    public CharSequence getPageTitle(int position) {
        String tagName = mFragmentsList.get(position).getTagName();
        tagName = tagName.replace("_", " ");
        return tagName;
    }

    @Override
    public boolean isViewFromObject(View view, Object object) {
        return object == view;
    }
}

Answer 1

当使用一个活动和多个片段时，我建议让片段管理UI 并使用Activity有一个控制器/模型。

微调器与其他片段通信的

工作流程：

在Frag1
在活动
从Frag1 OnItemSelected阻止活动从Spinner值更改
活动收到微调器更改值
活动调用Frag2侦听器以防止微调器更改的Frag2
Frag2接收微调更改，做你的东西

这是一个litle架构

activity/fragment communication with spinner

Answer 2

我会将所有内容都放在像Otto这样的事件总线上。恕我直言，碎片意味着与主机活动等脱钩，但所有接口和回调最终都会创建意大利面条代码。 Otto允许您在公共总线上发布事件 - 接收器不需要通过某些侦听器/回调机制绑定到发送器。此外，它与依赖注入结合使用效果很好，请参阅Dagger。

在片段之间进行通信

2 个答案:

这是一个litle架构