Android Modify activity heading style ActionBar

Modify the activity's heading style and Actionbar code as follows

    <!--application theme. -    <stylename= "Apptheme"Parent= "Appbasetheme">        <!--All customizations, that is, specific to a particular api-level can go. -        <!--<item name= "Android:windowbackground" > @color/darkblue</item> -        <!--<item name= "Android:colorbackground" > @color/darkblue</item> -        <Itemname= "Android:actionbarstyle">@style/myactionbarstyle</Item>     </style>    <stylename= "Myactionbarstyle"Parent= "Android:Widget.ActionBar">        <Itemname= "Android:background">@color/darkblue</Item>        <Itemname= "Android:titletextstyle">@style/acbar_titlestyle</Item>    </style>    <stylename= "Acbar_titlestyle">        <Itemname= "Android:textsize">18sp</Item>        <Itemname= "Android:textcolor">#FFFFFF</Item>    </style>

Modify the project Values/styles.xml add the style you want to redefine in <style name= "Apptheme" parent= "Appbasetheme" >.