Android ActionBar详解(六)--->利用ActionBar结合Fragment实现下拉式导航

MainActivity如下:

package cc.testsimpleactionbar5;import android.os.Bundle;import android.widget.ArrayAdapter;import android.app.ActionBar;import android.app.ActionBar.OnNavigationListener;import android.app.Activity;import android.app.FragmentTransaction;/** * Demo描述: * 利用ActionBar结合Fragment实现下拉式导航. * 且根据不同的导航利用Fragment显示不同的内容 *  * 备注说明: * 该示例和TestSimpleActionBar4示例的布局文件一致. * 代码实现也类似,只是导航方式不同罢了 *  * 参考资料: * 1 Android疯狂讲义(第二版) *   Thank you very much * */public class MainActivity extends Activity {    private ActionBar mActionBar;    private final static String SELECTED_PAGE_INDEX="selected_page";@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);initActionBar();}private void initActionBar(){mActionBar=getActionBar();//设置是否显示ActionBar的标题mActionBar.setDisplayShowTitleEnabled(true);//设置导航方式为LISTmActionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_LIST);ArrayAdapter<String> arrayAdapter=new ArrayAdapter<String>( MainActivity.this, android.R.layout.simple_list_item_1, android.R.id.text1,  new String[]{"第一页","第二页","第三页" });//为ActionBar设置ArrayAdapter和导航监听mActionBar.setListNavigationCallbacks(arrayAdapter,new NavigationListenerImpl());}private class NavigationListenerImpl implements OnNavigationListener{@Overridepublic boolean onNavigationItemSelected(int position, long id) {System.out.println(" onNavigationItemSelected ");TestFragment testFragment=new TestFragment();Bundle bundle=new Bundle();bundle.putString(TestFragment.KEY, "这是第"+(position+1)+"页");testFragment.setArguments(bundle);FragmentTransaction fragmentTransaction=getFragmentManager().beginTransaction();fragmentTransaction.replace(R.id.relativeLayoutContainer, testFragment);fragmentTransaction.commit();return false;}}// 以下处理横竖屏的切换// 将当前选中页的索引保存到Bundle中@Overrideprotected void onSaveInstanceState(Bundle bundle) {super.onSaveInstanceState(bundle);bundle.putInt(SELECTED_PAGE_INDEX,mActionBar.getSelectedNavigationIndex());}// 获取已经保存的被选中页的索引,且设置ActionBar.// setSelectedNavigationItem()方法会调用onNavigationItemSelected()@Overrideprotected void onRestoreInstanceState(Bundle bundle) {super.onRestoreInstanceState(bundle);mActionBar.setSelectedNavigationItem(bundle.getInt(SELECTED_PAGE_INDEX));}}

TestFragment如下:

package cc.testsimpleactionbar5;import android.app.Fragment;import android.os.Bundle;import android.view.Gravity;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.TextView;public class TestFragment extends Fragment {public static final String KEY="key";@Overridepublic View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {TextView textView=new TextView(getActivity());textView.setGravity(Gravity.CENTER);Bundle bundle=this.getArguments();String content=bundle.getString(KEY);textView.setText(content);textView.setTextSize(30);return textView;}}

main.mxl如下:

<RelativeLayout     xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:id="@+id/relativeLayoutContainer"    android:layout_width="match_parent"    android:layout_height="match_parent"    ></RelativeLayout>