Android Actionbar(標題欄)的背景設定

這東西Android官方文件是有的（點選開啟連結），這裡順便說下使用ActionbarSherlock時的設定。

For Android 3.0 and higher only（對於不需要相容2.x時可以直接如下設定）

When supporting Android 3.0 and higher only, you can define the action bar's background like this:

res/values/themes.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <!-- the theme applied to the application or activity -->
    <style name="CustomActionBarTheme"
           parent="@style/Theme.Holo.Light.DarkActionBar">
        <item name="android:actionBarStyle">@style/MyActionBar</item>
    </style>

    <!-- ActionBar styles 背景主要就是這裡設定了-->
    <style name="MyActionBar"
           parent="@style/Widget.Holo.Light.ActionBar.Solid.Inverse">
        <item name="android:background">@drawable/actionbar_background</item>
    </style>
</resources>

actionbar_background背景資源如下：

<?xml version="1.0" encoding="utf-8"?>
<color xmlns:android="http://schemas.android.com/apk/res/android" android:color="#7EC0EE">
</color>

For Android 2.1 and higher（需要相容2.x時要做的如下）

When using the Support Library, the same theme as above must instead look like this:

res/values/themes.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <!-- the theme applied to the application or activity -->
    <style name="CustomActionBarTheme"
           parent="@style/Theme.AppCompat.Light.DarkActionBar">
        <item name="android:actionBarStyle">@style/MyActionBar</item>

        <!-- Support library compatibility -->
        <item name="actionBarStyle">@style/MyActionBar</item>
    </style>

    <!-- ActionBar styles -->
    <style name="MyActionBar"
           parent="@style/Widget.AppCompat.Light.ActionBar.Solid.Inverse">
        <item name="android:background">@drawable/actionbar_background</item>

        <!-- Support library compatibility -->
        <item name="background">@drawable/actionbar_background</item>
    </style>
</resources>

ActionbarSherlock也類似這樣做，Theme.AppCompat.Light.DarkActionBar換成Theme.Sherlock.Light；Widget.AppCompat.Light.ActionBar.Solid.Inverse換成Widget.Sherlock.Light.ActionBar.Solid.Inverse 就行了

效果：