how to create a circular imageButton in android?

try to add this xml..

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" 
android:shape="rectangle">
<solid android:color="#eeffffff" />
<corners android:bottomRightRadius="8dip"
    android:bottomLeftRadius="8dip"  
    android:topRightRadius="8dip"
    android:topLeftRadius="8dip"/>
</shape>

Make a new shape XML in res/drawable/round_button.xml:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="oval" >
    <gradient 
        android:startColor="#FFFF0000" 
        android:endColor="#80FF00FF"
        android:angle="270" />
</shape>

Use this shape as the button's background:

<ImageButton
    android:id="@+id/imageButton1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:background="@drawable/round_button"
    android:src="@drawable/sliderr" />

You may also want to add android:scaleType="fitCenter" to your button to make the image the same size as the button, and android:adjustViewBounds="true" if your image has unequal height/width.

add android:background="@null"