Android FragmentTabHost呈现错误：没有标记为null

Question

我在我的应用程序中包含了一个FragmentTabHost。在xml布局中，FragmentTabHost没有出现在xml布局中。它显示以下内容：

Rendering problems:
Exception raised during rendering:No tab known for tag null

story_tab.xml：

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

    <android.support.v4.app.FragmentTabHost
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/tab_host">

            <FrameLayout
                android:id="@+id/tabcontent"
                android:layout_width="fill_parent"
                android:layout_height="0dp"
                android:layout_weight="1" />

    </android.support.v4.app.FragmentTabHost>

</LinearLayout>

StoryTab.java：

public class StoryTab extends AppCompatActivity {
    FragmentTabHost tabHost;
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.story_tab);
        tabHost=(FragmentTabHost) findViewById(R.id.tab_host);
        tabHost.setup(getApplicationContext(), getSupportFragmentManager(), R.id.tabcontent);
        tabHost.addTab(tabHost.newTabSpec("Stories").setIndicator("Stories"),StoryRecyclerLayout.class,savedInstanceState);
        tabHost.addTab(tabHost.newTabSpec("Publish").setIndicator("Publish"),StoryRecyclerLayout.class,savedInstanceState);
    }
}