在屏幕旋转时切换ListView ChoiceMode时出现问题

Question

我正在尝试基于Android文档末尾提供的有关Fragments 的示例代码构建拆分窗格,基本上是一个包含两个片段的LinearLayout(所有细节都可以在上面的链接中找到):

• TitlesFragment 显示标题列表
• DetailsFragment 显示当前所选标题的详细信息

我的问题是发生以下意外行为:

1. 我以横向方向启动应用程序:标题列表显示在左侧,当前所选标题的详细信息(开头的第一个)显示在右侧.
2. 我从标题列表中选择项目X:标题变为高亮显示,因为ListView设置为CHOICE_MODE_SINGLE并且其项目实现了Checkable界面.
3. 我切换到纵向方向(通过旋转设备或模拟器):正如预期的那样,只显示标题列表,并且在此配置中没有选择任何项目,因为ListView被重新创建,默认情况下,它被设置为CHOICE_MODE_NONE.
4. 我从标题列表中选择项目Y:如预期的那样,显示仅显示DetailsFragment与所做选择相对应的活动.
5. 我切换回横向方向(这里是意外行为发生的地方):DetailsFragment右侧正确显示项目Y的详细信息(以纵向方向选择),但TitlesFragment仍然显示项目X为选中(即之前选择的项目)第一个屏幕旋转).

当然,我希望在纵向方向上进行的最后一次选择也正确显示在其中TitlesFragment,否则我最终会出现一个不一致的突出显示,在显示项目Y的详细信息时显示项目X.

我发布了更改ListView模式的相关代码(在'onActivityCreated'中)并且设置了所选项(在'showDetails'方法中):

public static class TitlesFragment extends ListFragment {
boolean mDualPane;
int mCurCheckPosition = 0;

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

    // Populate list with our static array of titles.
    setListAdapter(new ArrayAdapter<String>(getActivity(),
            android.R.layout.simple_list_item_activated_1, Shakespeare.TITLES));

    // Check to see if we have a frame in which to embed the details
    // fragment directly in the containing UI.
    View detailsFrame = getActivity().findViewById(R.id.details);
    mDualPane = detailsFrame != null && detailsFrame.getVisibility() == View.VISIBLE;

    if (savedInstanceState != null) {
        // Restore last state for checked position.
        mCurCheckPosition = savedInstanceState.getInt("curChoice", 0);
    }

    if (mDualPane) {
        // In dual-pane mode, the list view highlights the selected item.
        getListView().setChoiceMode(ListView.CHOICE_MODE_SINGLE);
        // Make sure our UI is in the correct state.
        showDetails(mCurCheckPosition);
    }
}

@Override
public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    outState.putInt("curChoice", mCurCheckPosition);
}

@Override
public void onListItemClick(ListView l, View v, int position, long id) {
    showDetails(position);
}

/**
 * Helper function to show the details of a selected item, either by
 * displaying a fragment in-place in the current UI, or starting a
 * whole new activity in which it is displayed.
 */
void showDetails(int index) {
    mCurCheckPosition = index;

    if (mDualPane) {
        // We can display everything in-place with fragments, so update
        // the list to highlight the selected item and show the data.
        getListView().setItemChecked(index, true);

        // Check what fragment is currently shown, replace if needed.
        DetailsFragment details = (DetailsFragment)
                getFragmentManager().findFragmentById(R.id.details);
        if (details == null || details.getShownIndex() != index) {
            // Make new fragment to show this selection.
            details = DetailsFragment.newInstance(index);

            // Execute a transaction, replacing any existing fragment
            // with this one inside the frame.
            FragmentTransaction ft = getFragmentManager().beginTransaction();
            ft.replace(R.id.details, details);
            ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
            ft.commit();
        }

    } else {
        // Otherwise we need to launch a new activity to display
        // the dialog fragment with selected text.
        Intent intent = new Intent();
        intent.setClass(getActivity(), DetailsActivity.class);
        intent.putExtra("index", index);
        startActivity(intent);
    }
}

有没有人知道如何解决这个问题？提前致谢.

Answer 1

如果您将android:configChanges="orientation"活动标记放入清单文件中，您的应用程序将忽略旋转，但仍呈现相关布局。