requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);   
setContentView(R.layout.main);  //软件activity的布局 
getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.titlebar); //titlebar为自己标题栏的布局

<?xml version="1.0" encoding="utf-8"?> 
<resources xmlns:android="http://schemas.android.com/apk/res/android"> 
 
 
<style name="CustomWindowTitleBackground"> 
    <item name="android:background">#565656</item> 
</style> 
 
 
<style name="test" parent="android:Theme"> 
   <item name="android:windowTitleSize">50dp</item> 
   <item name="android:windowTitleBackgroundStyle">@style/CustomWindowTitleBackground</item> 
</style> 
</resources>

<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
   package="com.guardian" 
   android:versionCode="1" 
   android:versionName="1.0"> 
  <application android:icon="@drawable/icon" android:label="@string/app_name" > 
    <activity android:name=".Test" 
         android:label="@string/app_name" 
         android:theme = "@style/test"  //就在这里 
         > 
      <intent-filter> 
        <action android:name="android.intent.action.MAIN" /> 
        <category android:name="android.intent.category.LAUNCHER" /> 
      </intent-filter> 
    </activity> 
 
  </application> 
  <uses-sdk android:minSdkVersion="4" /> 
 
</manifest>