requestWindowFeature(Window.FEATURE_NO_TITLE)； 

android:theme="@android:style/Theme.NoTitleBar" 

MainActivity.java
package com.lingdududu.test; 
 
import android.app.Activity; 
import android.os.Bundle; 
import android.view.Window; 
 
public class MainActivity extends Activity { 
 /** Called when the activity is first created. */ 
 private boolean catchHomeKey = false; 
 public void onCreate(Bundle savedInstanceState) { 
 super.onCreate(savedInstanceState); 
 this.requestWindowFeature(Window.FEATURE_NO_TITLE); 
 setContentView(R.layout.main); 
  
 } 
} 

AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
 package="com.lingdududu.test" 
 android:versionCode="1" 
 android:versionName="1.0"> 
 <uses-sdk android:minSdkVersion="10" /> 
 
 <application android:icon="@drawable/icon" android:label="@string/app_name"> 
 <activity android:name=".MainActivity" 
   android:label="@string/app_name" 
   android:theme="@android:style/Theme.NoTitleBar" > 
  <intent-filter> 
  <action android:name="android.intent.action.MAIN" /> 
  <category android:name="android.intent.category.LAUNCHER" /> 
  </intent-filter> 
 </activity> 
 
 </application> 
</manifest> 

getWindow().setFlags(WindowManager.LayoutParams. FLAG_FULLSCREEN ,   
  WindowManager.LayoutParams. FLAG_FULLSCREEN); 
 
android:theme="@android:style/Theme.NoTitleBar.Fullscreen"