res/drawable/transparent_icon.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle" >

    <solid android:color="#00000000" />

</shape>
1	<?xml version="1.0" encoding="utf-8"?>
2	<shape xmlns:android="http://schemas.android.com/apk/res/android"
3	android:shape="rectangle" >
4
5	<solid android:color="#00000000" />
6
7	</shape>