title: How to change the background color of BottomSheet in Flutter?
body: <p><a href="https://i.stack.imgur.com/T9eS4.png" rel="noreferrer"><img src="https://i.stack.imgur.com/T9eS4.png" alt="Screenshot"></a></p>
  
  <p>When I use the showModalBottomSheet method to pop up a bottomSheet, how to make the background color transparent.
  because I needed the rounded corners, I knew that changing the canvasColor in the materialApp would do the trick, but other widgets would also change colors.</p>
  
  <p>I tried to embed it in the theme, but it didn't work</p>
  
  <pre><code>showModalBottomSheet &lt; Null &gt; (context: context, builder: (BuildContext context) {
      return Theme(
          data: Theme.of(context).copyWith(canvasColor: Colors.orange),
          child: Material(
              borderRadius: BorderRadius.only(topLeft: Radius.circular(16.0), topRight: Radius.circular(16.0)),
              child: Container(
                  color: Colors.purple,
              ),
          ),
      );
  });
  </code></pre>