centre button android
Center using a LinearLayout XML:
<LinearLayout
android:id="@+id/LinearLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:orientation="vertical" >
<ImageButton
android:id="@+id/btnFindMe"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@drawable/findme" />
</LinearLayout>