Centering source image (android:src) for ImageButton in Android

For centering android:src in the ImageButton I use the next solution.

First I need create 9-patch src image using next rules. Please look at the screenshot from draw9patch utility from Android SDK.

draw9patch utility

Next you need add the 9-patch image into ImageButton like this:

<ImageButton
android:layout_width="200dp"
android:layout_height="match_parent"
android:scaleType="fitXY"
android:src="@drawable/src_image" />

And finally you will get the next screen:

Result screen