为什么我得到相关的导致错误的小部件是:Scaffold?

Question

大家好，我想在脚手架内显示一些信息，但我得到了相关的导致错误的小部件是:Scaffold。即使我删除它，我仍然得到错误:

这是代码:

Widget build(BuildContext context) {
return Scaffold(
body: ExpansionTile(
title: Column(
mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Text(
widget.model.name,
overflow: TextOverflow.ellipsis,
),
Text(
widget.model.id.toString(),
style: Theme.of(context).textTheme.caption,
)
],
),
leading: SingleChildScrollView(
child: Column(
//  children: [
// Text(widget.model.mtu.toString()),
children: <Widget>[
StreamBuilder(
stream: widget.model.mtu,
initialData: 0,
builder: (c, snapshot) => ListTile(
title: const Text('MTU Size'),
subtitle: Text('${snapshot.data} bytes'),
),
// ],
),
],
),
),
trailing: TextButton(
onPressed: () {
setState(() {
buttonText = 'Connecting...';
});
widget.viewModel.establishConnectAndEnableNotify(widget.model);
},
child: Text(
buttonText,
style: TextStyle(color: AppColors.blue),
).tr(),
)));
}
}

如果你能帮助我，我将非常感激。

Answer 1

由于使用ListTile而发生的问题，它试图获得无限宽度。你可以用SizedBox包裹它并提供宽度。在顶层使用LayoutBuilder可以更好地获得父部件的宽度。

return Scaffold(
body: LayoutBuilder(
builder: (_, constraints) => ExpansionTile(
title: Column(
mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[],
),
leading: SingleChildScrollView(
child: Column(
//  children: [
// Text(widget.model.mtu.toString()),
children: <Widget>[
StreamBuilder(
// stream: "widget.model.mtu",
initialData: 0,
builder: (c, snapshot) => SizedBox(
width:
constraints.maxWidth * .2, //depend on you or hard-coded value
child: ListTile(
title: Text(' w ${constraints.maxWidth}'),
subtitle: Text('${snapshot.data} bytes'),
),
),
// ],
),
],
),
),

同时，我认为你不希望在leading上使用SingleChildScrollView，也许你喜欢在children上使用它