title: Android Make transparent half of view
body: <p>I can make an image button like "1" with android xml and bitmap repeat.</p>
  
  <p>But I want to make it like "2" (half transparent) with android xml. How can I make it?</p>
  
  <blockquote>
    <p><img src="https://i.stack.imgur.com/MLJpT.png" alt="enter image description here"></p>
  </blockquote>