一.添加标签 Tabs
在ActionBar中实现标签页可以实现android.app.ActionBar.TabListener ，重写onTabSelected、onTabUnselected和onTabReselected方法来关联Fragment。代码如下:
private class MyTabListener implements ActionBar.TabListener { private TabContentFragment mFragment; public TabListener(TabContentFragment fragment) { mFragment = fragment; } @Override public void onTabSelected(Tab tab, FragmentTransaction ft) { ft.add(R.id.fragment_content, mFragment, null); } @Override public void onTabUnselected(Tab tab, FragmentTransaction ft) { ft.remove(mFragment); } @Override public void onTabReselected(Tab tab, FragmentTransaction ft) { }}接下来我们创建ActionBar在Activity中，代码如下;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);final ActionBar actionBar = getActionBar(); //提示getActionBar方法一定在setContentView后面actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);actionBar.setDisplayOptions(0, ActionBar.DISPLAY_SHOW_TITLE);Fragment artistsFragment = new ArtistsFragment();actionBar.addTab(actionBar.newTab().setText(R.string.tab_artists).setTabListener(new TabListener(artistsFragment)));Fragment albumsFragment = new AlbumsFragment();actionBar.addTab(actionBar.newTab().setText(R.string.tab_albums).setTabListener(new TabListener(albumsFragment)));}二. 添加下拉导航 Drop-down Navigation:
创建一个SpinnerAdapter提供下拉选项，和Tab方式不同的是Drop-down只需要修改下setNavigationMode的模式，将ActionBar.NAVIGATION_MODE_TABS改为ActionBar.NAVIGATION_MODE_LIST，，最终改进后的代码为
ActionBar actionBar = getActionBar();actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_LIST);actionBar.setListNavigationCallbacks(mSpinnerAdapter, mNavigationCallback);上面我们通过setListNavigationCallbacks方法绑定一个SpinnerAdapter控件，具体的OnNavigationListener代码示例为;
mOnNavigationListener = new OnNavigationListener() { String[] strings = getResources().getStringArray(R.array.action_list); @Override public boolean onNavigationItemSelected(int position, long itemId) { ListContentFragment newFragment = new ListContentFragment(); FragmentTransaction ft = openFragmentTransaction(); ft.replace(R.id.fragment_container, newFragment, strings[position]); ft.commit(); return true;}};而其中的ListContentFragment的代码为:
public class ListContentFragment extends Fragment {private String mText;@Overridepublic void onAttach(Activity activity) {super.onAttach(activity);mText = getTag();}@Overridepublic View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {TextView text = new TextView(getActivity());text.setText(mText);return text;}}
没有早一步，也没有晚一步，刚好遇上了你！
