Sliver app bar

CustomScrollView(
    slivers: <Widget>[
      SliverAppBar(
        title: Text('SliverAppBar'),
        backgroundColor: Colors.green,
        expandedHeight: 200.0,
        flexibleSpace: FlexibleSpaceBar(
          background: Image.asset('assets/forest.jpg', fit: BoxFit.cover),
        ),
      ),
      SliverFixedExtentList(
        itemExtent: 150.0,
        delegate: SliverChildListDelegate(
          [
            Container(color: Colors.red),
            Container(color: Colors.purple),
            Container(color: Colors.green),
            Container(color: Colors.orange),
            Container(color: Colors.yellow),
            Container(color: Colors.pink),
          ],
        ),
      ),
    ],
);