flutter: no refresh indicator when using RefreshIndicator

Question

I added the RefreshIndicator to my page, but there is no indicator visible when pull to refresh. The code is below:

class HomePage extends StatefulWidget {
  HomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => new _MyHomePageState();
}

class _MyHomePageState extends State<HomePage> {

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: new Text(widget.title),
      ),
      body: LocalGalleryTab(),
    );
  }
}

class LocalGalleryTab extends StatefulWidget {
  @override
  State<StatefulWidget> createState() {
    return _LocalGalleryState();
  }
}

class _LocalGalleryState extends State<LocalGalleryTab> {
  @override
  Widget build(BuildContext context) {
    return new Container(child: new Center(
      child: new RefreshIndicator(
        child: Text("Local Gallery"),
        onRefresh: _refreshLocalGallery,
      ),
    ));
  }

  Future<Null> _refreshLocalGallery() async{
    print('refreshing stocks...');

  }
}

How to use the RefreshIndicator? The flutter doc does not give much infomation.

Answer 1

You need to add scroll child inside RefreshIndicator see example below

class HomePage extends StatefulWidget {
  HomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => new _MyHomePageState();
}

class _MyHomePageState extends State<HomePage> {

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: new Text(widget.title),
      ),
      body: LocalGalleryTab(),
    );
  }
}

class LocalGalleryTab extends StatefulWidget {
  @override
  State<StatefulWidget> createState() {
    return _LocalGalleryState();
  }
}

class _LocalGalleryState extends State<LocalGalleryTab> {
  @override
  Widget build(BuildContext context) {
    return RefreshIndicator(
        child: ListView(
          children: List.generate(50,  (f) => Text("Item $f")),
        ),
        onRefresh: _refreshLocalGallery,
      );
  }

  Future<Null> _refreshLocalGallery() async{
    print('refreshing stocks...');

  }
}