android - ButtonView with different background -

i have designed rounded corners button.

button_selector.xml:

<?xml version="1.0" encoding="utf-8"?> <shape xmlns:android="http://schemas.android.com/apk/res/android"     android:shape="rectangle" >     <corners android:radius="10dp"/>  </shape> 

in layout:

<button    android:background="@drawable/button_selector" .../> 

on every click color of should button changes :

in activity, inside onclicklistener():

btn1.setbackgroundcolor(getanswercolor(choicearray[0])); 

but if this, not getting rounder corners.

how rounder corners? please suggest.

btn1.setbackgroundresource(r.drawable.button_selector);  gradientdrawable drawablegradient = (gradientdrawable) btn1.getbackground(); drawablegradient .setcolor(color.red);