Step 1: Create an XML in the drawable folder and name it selected_item.xml (or any another name you want but to be suggestive). The code in this xml will be:
<shape android="http://schemas.android.com/apk/res/android" shape="rectangle"> <solid color="#80000000"></solid> </shape>
The color=”#80000000″ is transparent black.
Step 2: Create an XML again, in the drawable folder an name it not_selected.xml. The code in this xml will be:
<shape android="http://schemas.android.com/apk/res/android" shape="rectangle"> <solid color="#80ffffff"></solid> </shape>
The color=”#80ffffff” is transparent white.
Step 3 Create an XML again :) in the drawable folder and name it button_selector.xml. The code in this xml will be:
<selector android="http://schemas.android.com/apk/res/android"> <item drawable="@drawable/selected" state_focused="false" state_pressed="true"></item> <item drawable="@drawable/not_selected"> </item> </selector>
Step 4 In the xml file where you make the button put this:
android:background="@drawable/button_selector"