android中开启actionbar的两种方法

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"     package="com.baidu.homer"     android:versionCode="1"     android:versionName="1.0">  <uses-sdk android:minSdkVersion="18"/>  <application android:label="@string/app_name" android:icon="@drawable/ic_launcher"      android:theme="@android:style/Theme.Holo">    <activity android:name="MyActivity"         android:label="@string/app_name">      <intent-filter>        <action android:name="android.intent.action.MAIN"/>        <category android:name="android.intent.category.LAUNCHER"/>      </intent-filter>    </activity>  </application></manifest>

import android.app.ActionBar;import android.app.Activity;import android.drm.DrmStore;import android.os.Bundle;public class MyActivity extends Activity {  /**   * Called when the activity is first created.   */  @Override  public void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.main);    ActionBar actionBar = getActionBar();    actionBar.show();  }}