Animate the outer stroke of a view (button)

I'd like to flash/blink the stroke of a button a few times based on a timer. For example, every 30 se开发者_StackOverflow中文版conds flash the stroke 3 times from white to black or some such thing. Can this be done? Thanks

you can create custom button layouts like such and put them in the drawable folder

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

<item>        
    <shape>
        <gradient
            android:endColor="@color/white"
            android:startColor="@color/whitesmoke"
            android:angle="270" />
        <stroke
            android:width="2dp"
            android:color="@color/grey3" />
        <corners
            android:radius="10dp" />
    </shape>
</item>

where the color grey3 is the border and you can start a timer and add a TimerTask class to your class and then make it run the task every 30 seconds and just change the buttons background from one .xml to another with a different border color.