title: How to set shape's opacity?
body: <p>I already know how to set the opacity of the background image but I need to set the opacity of my shape object.</p>
  
  <p>In my Android app, I have it like this:
  <img src="https://i.stack.imgur.com/jLQZD.png" alt="enter image description here"></p>
  
  <p>and I want to make this black area a bit transparent, like here, for example I can see circles though this "Welcome..." :</p>
  
  <p><img src="https://i.stack.imgur.com/MnUQF.png" alt="enter image description here"></p>
  
  <p>Here is my shape code:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;shape xmlns:android="http://schemas.android.com/apk/res/android"
      android:id="@+id/shape_my""&gt;
      &lt;stroke android:width="4dp" android:color="#636161" /&gt;
      &lt;padding android:left="20dp"
          android:top="20dp"
          android:right="20dp"
          android:bottom="20dp" /&gt;
      &lt;corners android:radius="24dp" /&gt;
  &lt;/shape&gt;
  </code></pre>
  
  <p>How can I do that?  </p>