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";
	@Override
	protected 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LIST
		mActionBar.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{
		@Override
		public 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
	@Override
	protected 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()
	@Override
	protected 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";
	@Override
	public 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>