Android - 一个选项卡中的多个片段

我在网上搜索了很多有关在一个操作栏选项卡中包含多个片段的可能性的信息。

这个问题最接近我的需求，但代码不起作用。

是否有另一种可能性可以在一个选项卡中包含多个片段？

这是StartActivity

public class StartActivity extends FragmentActivity implements ActionBar.TabListener {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_start);

        // Set up the action bar.
        final ActionBar actionBar = getActionBar();
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

        actionBar.addTab(
              actionBar.newTab()
             .setText("Karte")
              .setTabListener(new MapFragmentListener(this)));

    }

对应布局acticity_start包含将放置在选项卡中的两个片段的两个框架布局。

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >  

    <FrameLayout
        android:id="@+id/fragment_map"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"/>
    <FrameLayout
        android:id="@+id/fragment_realtime"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"/>

</LinearLayout>

The TabListener看起来像这样：

private class TabListener implements ActionBar.TabListener {

        private static final String fragment1_tag = "fragment1_tag";
        private static final String fragment2_tag = "fragment2_tag";

        private FragmentActivity activity;
        private RealtimeFragment fragment1;
        private RealtimeFragment fragment2;

        public TabListener(FragmentActivity activity) {

            this.activity = activity;

            android.support.v4.app.FragmentTransaction ft = activity.getSupportFragmentManager().beginTransaction();

            fragment1 = (RealtimeFragment) activity.getSupportFragmentManager().findFragmentByTag(fragment1_tag);
            if (fragment1 != null && !fragment1.isDetached()) {
                ft.detach(fragment1);
            }

            fragment2 = (RealtimeFragment) activity.getSupportFragmentManager().findFragmentByTag(fragment2_tag);
            if (fragment2 != null && !fragment2.isDetached()) {
                ft.detach(fragment2);
            }

            ft.commit();
        }

        @Override
        public void onTabReselected(Tab tab, FragmentTransaction ft) {
            // TODO Auto-generated method stub

        }

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

            android.support.v4.app.FragmentTransaction fragmentTransaction = activity.getSupportFragmentManager().beginTransaction();

            if(fragment1 == null) {
                fragment1 = new RealtimeFragment();
                fragmentTransaction.add(R.id.fragment_map, fragment1, fragment1_tag);
            } else {
                fragmentTransaction.attach(fragment1);
            }


            if(fragment2 == null) {
                fragment2 = new RealtimeFragment();
                fragmentTransaction.add(R.id.fragment_realtime, fragment2, fragment2_tag);
            } else {
                fragmentTransaction.attach(fragment2);
            }


            fragmentTransaction.commit();

        }

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

            android.support.v4.app.FragmentTransaction fragementTransaction = activity.getSupportFragmentManager().beginTransaction();

            if(fragment1_tag != null)
                fragementTransaction.detach(fragment1);
            if(fragment2 != null)
                fragementTransaction.detach(fragment2);


            fragementTransaction.commit();

        }

    }

班上RealtimeFragment以及相应的布局fragment_realtime看起来像这样：

public class RealtimeFragment extends Fragment {

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


<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button" />

</LinearLayout>

现在在一个选项卡中包含该类的两个片段RealtimeFragment应该显示。这些片段只显示一个按钮，但什么也没有显示！为什么？

我正在寻找同一主题的解决方案，并发现了这个，它非常方便。

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <fragment android:name="com.example.news.ArticleListFragment"
            android:id="@+id/list"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="match_parent" />
    <fragment android:name="com.example.news.ArticleReaderFragment"
            android:id="@+id/viewer"
            android:layout_weight="2"
            android:layout_width="0dp"
            android:layout_height="match_parent" />
</LinearLayout>

所以引用你的片段并对其进行充气，就像普通的片段一样