title: how to setImage to null in android when the xml has src not null?
body: <p>I have this xml</p>
  
  <pre><code>&lt;ImageView
      android:id="@+id/ImgOn"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_gravity="center"
      android:src="@drawable/icon_on" /&gt;
  </code></pre>
  
  <p>I want to remove this image sometimes via code. I've seen many posts like <a href="https://stackoverflow.com/questions/2859212/how-to-clear-an-imageview-in-android">this</a>,
  but in my case <code>imageButton.setBackgroundResource(0);</code> leaves the default image which appears in my xml layout.</p>
  
  <p>How would you remove it programmatically? I heard transparent color crashes some old devices.</p>
  
  <p><strong>update</strong></p>
  
  <p>setImageResource(0) left the xml's original src as well and not null as i want it to be</p>