title: Can't change background of actionbar in Android Studio
body: <p>I want to change the background of actionbar but it doesn't work. The code is rather simple:</p>
  
  <pre><code>&lt;style name="AppTheme" parent="@style/Theme.AppCompat.Light"&gt;
      &lt;!-- Customize your theme here. --&gt;
      &lt;item name="android:actionBarStyle"&gt;@style/ActionBarTheme&lt;/item&gt;
  &lt;/style&gt;
  
  &lt;style name="ActionBarTheme"
  parent="@style/Widget.AppCompat.Light.ActionBar.Solid.Inverse"&gt;
      &lt;item name="android:background"&gt;@drawable/green1&lt;/item&gt;
      &lt;item name="background"&gt;@drawable/green1&lt;/item&gt;
  &lt;/style&gt;
  
  &lt;activity
      android:name=".MainActivity"
      android:label="@string/app_name"
      android:theme="@style/AppTheme"&gt;
  &lt;/activity&gt;
  </code></pre>
  
  <p>green1 is a picture in drawable. I run the program, the actionbar shows as the default theme instead of the picture I want. What is the problem? Really confused.</p>