ActionBar下拉式导航

来源：互联网发布：csgo优化指令编辑：程序博客网时间：2024/04/30 02:42

第一步：编写布局文件：

<?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="horizontal"    android:id="@+id/container"></LinearLayout>

第二步：编写Activity代码：

public class DropdownTabActivity extends Activity implements ActionBar.OnNavigationListener{    private static final String SELECTED_ITEM = "selected_item";    ActionBar actionBar;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.tab);        actionBar = getActionBar();        //  设置ActionBar显示标题        actionBar.setDisplayShowTitleEnabled(true);        //  设置ActionBar的导航模式        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_LIST);        actionBar.setListNavigationCallbacks(                new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,                        android.R.id.text1,new String[]{"第一页","第二页","第三页"}),this);    }    //  当点击一个Tab选项时触发    @Override    public boolean onNavigationItemSelected(int itemPosition, long itemId) {        Fragment fragment = new DummyFragment();        Bundle args = new Bundle();        args.putInt(DummyFragment.ARG_SECTION_NUMBER,itemPosition+1);        fragment.setArguments(args);        FragmentTransaction transaction = getFragmentManager().beginTransaction();        transaction.replace(R.id.container,fragment);        transaction.commit();        return false;    }    @Override    protected void onSaveInstanceState(Bundle outState) {        super.onSaveInstanceState(outState);        //   将已选择的ActionBar的索引值存到Bundle数据中KEY为SELECTED_ITEM中去        outState.putInt(SELECTED_ITEM,getActionBar().getSelectedNavigationIndex());    }    @Override    protected void onRestoreInstanceState(Bundle savedInstanceState) {        super.onRestoreInstanceState(savedInstanceState);        //   设置ActionBar的导航索引值        getActionBar().setSelectedNavigationItem(savedInstanceState.getInt(SELECTED_ITEM));    }}

其中 DummyFragment代码如下：

public class DummyFragment extends Fragment {    public final static String ARG_SECTION_NUMBER = "section_number";    @Override    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {        TextView textView = new TextView(getActivity());        textView.setGravity(Gravity.START);        Bundle args = getArguments();        textView.setText(args.getInt(ARG_SECTION_NUMBER)+"");        textView.setTextSize(28);        return textView;    }}

运行效果如下：

0 0