title: How can fix ListView in column and add RefreshIndicator to the ListView
body: <p>I have a ListView in column ,and need add RefreshIndicator to the ListView,but it not work well
  I tried contain the listView by Expanded,then list display well,but when call the RefreshIndicator ,app dump...
  some one can help me ,how to fix this code,thanks</p>
  
  <pre><code>import 'dart:async';
  
  import 'package:flutter/material.dart';
  
  void main() {
    runApp(new MaterialApp(
      home: new MyApp(),
    ));
  }
  
  class MyApp extends StatefulWidget {
    @override
    State&lt;StatefulWidget&gt; createState() =&gt; MyAppState();
  }
  
  class MyAppState extends State&lt;MyApp&gt; {
    List&lt;int&gt; items = List.generate(16, (i) =&gt; i);
  
    Future&lt;Null&gt; _handleRefresh() async {
      await Future.delayed(Duration(seconds: 5), () {
        print('refresh');
        setState(() {
          items.clear();
          items = List.generate(40, (i) =&gt; i);
          return null;
        });
      });
    }
  
    @override
    Widget build(BuildContext context) {
      return Scaffold(
          appBar: AppBar(
            title: Text("Refresh"),
          ),
          body:  Column(
            children: &lt;Widget&gt;[RefreshIndicator(child:
              ListView.builder(
                itemCount: items.length,
              shrinkWrap: true,
                itemBuilder: (context, index) {
                  return ListTile(
                    title: Text("Index$index"),
                  );
                },
               ), onRefresh: _handleRefresh,)
            ],
          )
  
          );
    }
  }
  </code></pre>