title: How to change button's size in checkbox
body: <p>I tried to change Button in Checkbox by using png file, but the image was too big and it made the Button too big.</p>
  
  <p>I want to change the Button's size to 20dp.
  Then I set layout_width and layout_height in CheckBox, but it didn't solve the problem.</p>
  
  <p>Could you please teach me how to change the size?</p>
  
  <pre><code>&lt;CheckBox
      android:layout_width="20dp"
      android:layout_height="20dp"
      android:text="New CheckBox" 
      android:layout_margin="5dp"
      android:button="@drawable/my_check_box"
      android:layout_weight="1" /&gt;
  </code></pre>
  
  <p>my_check_box.xml</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;selector xmlns:android="http://schemas.android.com/apk/res/android"&gt;
      &lt;item android:state_checked="false"
          android:drawable="@drawable/checkbox_normal" /&gt;
      &lt;item android:state_checked="true"
          android:drawable="@drawable/checkbox_selected" /&gt;
  &lt;/selector&gt;
  </code></pre>