Flutter：让ListView在底部弹跳，在顶部位置夹紧

Question

有两种类型的ScrollPhysics，我想申请我的ListView。当用户到达列表底部时，我想要BouncingScrollPhysics()发生，但是当用户到达顶部时，它不应该反弹而应该执行ClampingScrollPhysics()。如何实现这一目标？

Answer 1

截屏：

// create 2 instance variables
var _controller = ScrollController();
ScrollPhysics _physics = ClampingScrollPhysics();

@override
void initState() {
  super.initState();
  _controller.addListener(() {
    if (_controller.position.pixels <= 56)
      setState(() => _physics = ClampingScrollPhysics());
    else
      setState(() => _physics = BouncingScrollPhysics());
  });
}

@override
Widget build(BuildContext context) {
  return Scaffold(
    body: ListView.builder(
      controller: _controller,
      physics: _physics,
      itemCount: 20,
      itemBuilder: (_, i) => ListTile(title: Text("Item $i")),
    ),
  );
}