当我单击pariticular选项卡并附加图像时，我想更改选项卡背景颜色

Question

这是我的MainActivity

public class MainActivity extends Activity {

    // Declaring our tabs and the corresponding fragments.
    ActionBar.Tab photosTab, videosTab;
    Fragment photoTab = new Photos();
    Fragment videoTab = new Videos();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Asking for the default ActionBar element that our platform supports.
        ActionBar actionBar = getActionBar();

        // Screen handling while hiding ActionBar icon.
        actionBar.setDisplayShowHomeEnabled(false);

        // Screen handling while hiding Actionbar title.
        actionBar.setDisplayShowTitleEnabled(false);

        // Creating ActionBar tabs.
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);



        // Setting custom tab icons.
        photosTab = actionBar.newTab().setText("PHOTOS");
        videosTab = actionBar.newTab().setText("VIDEOS");

        // Setting tab listeners.
        photosTab.setTabListener(new TabListener(photoTab));
        videosTab.setTabListener(new TabListener(videoTab));


        // Adding tabs to the ActionBar.
        actionBar.addTab(photosTab);
        actionBar.addTab(videosTab);

    }
}

这是TabListener类

public class TabListener implements ActionBar.TabListener {

    private Fragment fragment;

    // The contructor.
    public TabListener(Fragment fragment) {
        this.fragment = fragment;
    }

    // When a tab is tapped, the FragmentTransaction replaces
    // the content of our main layout with the specified fragment;
    // that's why we declared an id for the main layout.
    @Override
    public void onTabSelected(Tab tab, FragmentTransaction ft) {
        ft.replace(R.id.activity_main, fragment);

    }

    // When a tab is unselected, we have to hide it from the user's view. 
    @Override
    public void onTabUnselected(Tab tab, FragmentTransaction ft) {
        ft.remove(fragment);
    }

    // Nothing special here. Fragments already did the job.
    @Override
    public void onTabReselected(Tab tab, FragmentTransaction ft) {

    }
}

在tabListener类中，我在onTabUnselected方法中使用了switch case，但它没有用......而且我在mainActivity中使用了setBackgroundDrawable ....没有用...