title: Why the ListView in Flutter doesn't apply height?
body: <p>I have a simple code:</p>
  
  <pre><code>class App extends StatelessWidget {
    @override
    Widget build(BuildContext context) {
      return Directionality(
        textDirection: TextDirection.ltr,
        child: Container(
          padding: EdgeInsets.symmetric(vertical: 60.0,),
          color: Color(0xFF24323F),
          child: Container(
            color: Colors.green,
            margin: EdgeInsets.symmetric(vertical: 10.0),
            height: 200.0,
          ),
        ),
      );
    }
  }
  </code></pre>
  
  <p>I try to change the height of a Container but It doesn't work. Why?</p>
  
  <p>The result of render:
  <a href="https://i.stack.imgur.com/B7by6.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/B7by6.png" alt="enter image description here"></a></p>