title: error event onclick of RadioButton in .xml
body: <p>When I add an on click event in .xml I don't have and error like this</p>
  <p><img src="https://i.stack.imgur.com/nnPJu.png" alt="enter image description here" /></p>
  <p>Here is my code</p>
  <pre><code>&lt;RadioButton 
      android:id=&quot;@+id/dientich&quot; 
      android:layout_width=&quot;wrap_content&quot; 
      android:layout_height=&quot;wrap_content&quot;
      android:onClick=&quot;onClickHandler&quot;
      android:text=&quot;dien tich&quot; /&gt;
  &lt;RadioButton
      android:id=&quot;@+id/thetich&quot;
      android:onClick=&quot;&quot;
      android:layout_width=&quot;wrap_content&quot; 
      android:layout_height=&quot;wrap_content&quot;
      android:layout_marginLeft=&quot;30dp&quot;
      android:text=&quot;the tich&quot; /&gt;
   &lt;/RadioGroup&gt;
  </code></pre>
  <p>Thank you!</p>