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();
  }
}