title: Flutter- Drop Down Button issue
body: <p>Flutter is Amazing, and so is its widgets and extensive Documentation.  <a href="https://github.com/flutter/flutter/issues/9211" rel="nofollow noreferrer">I have an issue understanding a possible work around for an issue that is already filed in GitHub issues by many users, This Url will help you learn about the issue for Flutter's Dropdown Button and also the proposed work arounds</a>. I am facing the same issue. There is a possible work around mentioned by Brian Egan in the link, however, I am not sure how to implement the same. I tried to comprehend the mentioned steps and achieve the desired result. However if I add an Expanded widget in my DropdownMenuItem, inside my DropdownButton Widget, it gives me an error for incorrect ParentWidget. </p>
  
  <p>It would be great if someone illustrated the work around to me, anyone who can give me a better explanation. </p>
  
  <p>Note: The issue is currently open, so its alright if we end up relying on the core team for this. But I believe there exists a simple work around here. </p>
  
  <p>As requested in the comments, here is the sample code:</p>
  
  <pre><code>``` new DropdownButton(
        value: value,
        onChanged: (string) =&gt; setState(() =&gt; value = string),
        items: Items.map((string) {
          return new DropdownMenuItem(
            child: new Text(string),
            value: string,
          );
        }).toList(),```
  </code></pre>