Here I am writing code to create transparent button with border.

First create xml file transparent_button.xml for selector where I am describing the properties of button like border width, color etc

<!--?xml version="1.0" encoding="utf-8"?-->

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape android:shape="rectangle">


     <solid android:color="#00ffffff"/>

        <stroke android:color="@android:color/white" android:width="1dp"/>
        <corners android:radius="4dp"/>
    </shape>
</item>

Then use Button like this

<button android:id="@+id/button"
 android:layout_width="match_parent" 
 android:layout_height="wrap_content" 
 android:background="@mipmap/transparent_button" />