Android实现隐藏状态栏和标题栏

<?xml version="1.0" encoding="utf-8"?> 
<manifest 
  xmlns:android="http://schemas.android.com/apk/res/android"   
  package="de.vogella.android.temperature"   
  android:versionCode="1"   
  android:versionName="1.0">   
  <application 
     android:icon="@drawable/icon" 
     android:label="@string/app_name">     
    <activity 
         android:name=".Convert"
         android:label="@string/app_name"
         android:theme="@android:style/Theme.NoTitleBar.Fullscreen" >
       <intent-filter>
         <action android:name="android.intent.action.MAIN" />
         <category android:name="android.intent.category.LAUNCHER" />
       </intent-filter>
     </activity>      
  </application>   


  <uses-sdk android:minSdkVersion="9" />
</manifest> 

@Override
public void onCreate(Bundle savedInstanceState) {
   super.onCreate(savedInstanceState);
   // hide titlebar of application
   // must be before setting the layout
   requestWindowFeature(Window.FEATURE_NO_TITLE);
   // hide statusbar of Android
   // could also be done later
   getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
       WindowManager.LayoutParams.FLAG_FULLSCREEN);
   setContentView(R.layout.main);
   text = (EditText) findViewById(R.id.EditText01);
    }