title: Round the edges of a DropdownButtons's list of items
body: <p>How can I round the edges of a DropdownButton's opened list that holds the DropDownButtonItems?</p>
  <p><a href="https://i.stack.imgur.com/qssHm.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/qssHm.png" alt="enter image description here" /></a></p>
  <p>This is what I have:</p>
  <pre><code>String selectedValue;
  
  DropdownButtonHideUnderline(
    child: DropdownButton&lt;String&gt;(
      style: TextStyle(
        fontWeight: FontWeight.w600,
        fontSize: 18,
        color: Colors.black,
      ),
      isExpanded: true,
      value: selectedValue, //var that
      items: getDropdownItems4(), //simple function that holds the values of all the items
      onChanged: (String value) {
        setState(() {
          selectedValue = value;
        });
      },
    ),
  ),
  </code></pre>