java - 让 Actionbar 标签贴在 Fragment 上

Question

我目前有一个 MainActivity.java，它应该是唯一的 Activity 类。虽然在那个 Activity 类中我有一个抽屉导航链接到其他 fragment View 。

目前我面临的主要问题是在 fragment 下实现选项卡并使它们仅可用于该 fragment 和子 fragment 。我运行了我的应用程序并出现了选项卡，但在我访问 TeamsAndDriversFragment 后它们也出现在其他 fragment 上。

在我的 MainActivity.java 中，我有以下函数，它有助于指向当有人在抽屉导航中单击它们时它将生成的 fragment :

/**
 * Diplaying fragment view for selected nav drawer list item
 * */
private void displayView(int position) {
    // update the main content by replacing fragments
    Fragment fragment = null;
    switch (position) {
        case 0:
            fragment = new TimeAndScoringFragment();
            break;
        case 1:
            fragment = new ScheduleFragment();
            break;
        case 2:
            fragment = new StandingsFragment();
            break;
        case 3:
            fragment = new TeamsAndDriversFragment();
            break;
        case 4:
            fragment = new NewsFragment();
            break;
        default:
            break;
    }

    if (fragment != null) {

        // Create a fragment transaction object to be able to switch fragments
        FragmentTransaction transaction = getFragmentManager().beginTransaction();

        // Replace whatever is in the fragment container view with this fragment,
        // and add the transaction to the back stack
        transaction.replace(R.id.frame_container, fragment);
        transaction.addToBackStack(null);

        // Commit the transaction
        transaction.commit();

        // update selected item and title, then close the drawer
        mDrawerList.setItemChecked(position, true);
        mDrawerList.setSelection(position);
        setTitle(navMenuTitles[position]);
        mDrawerLayout.closeDrawer(mDrawerList);

    } else {
        // error in creating fragment
        Log.e("MainActivity", "Error in creating fragment");
    }
}

这是我当前的 TeamsAndDriversFragment 类，其中我有一个带有选项卡的操作栏导航:

public class TeamsAndDriversFragment extends Fragment implements TabListener {

private List<Fragment> fragList = new ArrayList<Fragment>();

@Override
public void onCreate(Bundle savedInstance) {
    super.onCreate(savedInstance);

    ActionBar bar = getActivity().getActionBar();

    bar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

    Tab mTeamsTab = bar.newTab();
    mTeamsTab.setText("Teams");
    mTeamsTab.setTabListener(this);
    bar.addTab(mTeamsTab);

    Tab mDriversTab = bar.newTab();
    mDriversTab.setText("Drivers");
    mDriversTab.setTabListener(this);
    bar.addTab(mDriversTab);
}

@Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {

}

@Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
    Fragment f = null;
    TabFragment tf = null;

    if(fragList.size() > tab.getPosition()) {
        fragList.get(tab.getPosition());
    }

    if(f == null) {
        tf = new TabFragment();
        Bundle data = new Bundle();
        data.putInt("idx", tab.getPosition());
        tf.setArguments(data);
        fragList.add(tf);
    } else {
        tf = (TabFragment) f;
    }

    ft.replace(android.R.id.content, tf);
}

@Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
    if(fragList.size() > tab.getPosition()) {
        ft.remove(fragList.get(tab.getPosition()));
    }
}


}

Answer 1

在 displayView() 方法中，只需从 ActionBar 中删除所有选项卡，这样您将始终拥有一个干净的 ActionBar TeamsAndDriversFragment fragment 的异常:

private void displayView(int position) {
     getSupportActionBar().removeAllTabs();
     // ...
}