SherlockFragmentActivity with TabHost, the item activity getActionBar null

[liufsd]

I have to build a SherlockFragmentActivity with TabHost,and tab's item also use SherlockFragmentActivity.

//TabManagerActivity.java
TabManagerActivity extends SherlockFragmentActivity
{
  private TabHost tabHost;
  protected void onCreate(Bundle savedInstanceState) {
   .....
    tabHost = (TabHost) findViewById(R.id.tabHost);
  ....
      tabHost.addTab(tabHost,.....ItemSearchActivity.class);
...
}
}

//ItemSearchActivity.java

ItemSearchActivity extends SherlockFragmentActivity
{
.....
 protected void onCreate(Bundle savedInstanceState) {

...
getSupportActionBar() = null //  can not get actionBar here. why ???
}

}

[JakeWharton]

Nested activities do not have action bars. This is how the platform behaves.