title: Flutter Container Layout behavior
body: <p>when i read the Container layout behavior of <a href="https://docs.flutter.io/flutter/widgets/Container-class.html" rel="nofollow noreferrer">Container document</a>:</p>
  
  <blockquote>
    <p>If the widget has no child, no height, no width, no constraints, and the parent provides unbounded constraints, then Container tries to size as small as possible.</p>
  </blockquote>
  
  <p>so i write some code like below ,i think the second container should be as small as possible,but it fill the application’s content area (the entire screen) ，why? </p>
  
  <pre><code>class ContainerWithScaffold extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
  return new MaterialApp(
    title: 'Container with scaffold',
    home: Scaffold(
      body: Container(
        color: Colors.blue,
        height: double.infinity,// provides unbounded height constraints for the child container
        width: double.infinity,// provides unbounded width constraints for the child container
        child: new Container(
          color: Colors.white,
        ),
      ),
    ),
  );
  }
  }
  </code></pre>