Je veux avoir un ListView dans un autre widget, lorsque FutureBuilder dans une Column afin d'avoir une Row simple. J'obtiens cette erreur:
class ActivityShowTicketReplies extends StatefulWidget {
final Map<String, dynamic> ticketData;
ActivityShowTicketReplies({@required this.ticketData});
@override
State<StatefulWidget> createState() => ActivityShowTicketRepliesState();
}
class ActivityShowTicketRepliesState extends State<ActivityShowTicketReplies> {
TicketsTableData get _ticket => TicketsTableData.fromJson(json.decode(widget.ticketData.values.toList()[0][0].toString()));
@override
Widget build(BuildContext context) {
return ScopedModel(
model: CounterModel(),
child: Directionality(
textDirection: TextDirection.rtl,
child: Scaffold(
body: Column(
children: <Widget>[
Row(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
Padding(
padding: const EdgeInsets.symmetric(vertical: 20.0),
child: RaisedButton(
color: Colors.indigo,
onPressed: () => BlocProvider.of<AppPagesBloc>(context).dispatch(FragmentNavigateEvent(routeName: FRAGMENT_NEW_TICKET)),
shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(50.0)),
child: Container(
child: Text(
'new ticket',
style: AppTheme(context).caption().copyWith(color: Colors.white),
),
),
),
),
],
),
FutureBuilder(
future: Provider.of<TicketRepliesTableDao>(context).find(ticketId: _ticket.id),
builder: (context, snapshot) {
if (snapshot.connectionState == ConnectionState.done) {
if (snapshot.hasData) {
final List<TicketRepliesTableData> ticketReplies = snapshot.data;
if (ticketReplies.isNotEmpty) {
return Column(
children: <Widget>[
Card(
clipBehavior: Clip.antiAlias,
color: Colors.grey[50],
margin: EdgeInsets.all(10.0),
child: InkWell(
child: Stack(
children: <Widget>[
Column(
children: <Widget>[
Padding(
padding: const EdgeInsets.symmetric(vertical: 12.0),
child: ListTile(
title: Padding(
padding: const EdgeInsets.symmetric(vertical: 5.0),
child: Text(
'subject',
style: AppTheme(context).caption().copyWith(fontFamily: 'ShabnamBold'),
),
),
subtitle: Text(
_ticket.subject,
style: AppTheme(context).caption(),
),
),
),
Container(
height: 30.0,
margin: EdgeInsets.zero,
width: double.infinity,
color: Colors.grey[200],
child: Row(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
],
),
),
],
),
Align(
alignment: Alignment.topLeft,
child: Container(
margin: EdgeInsets.only(top: 10.0),
constraints: BoxConstraints(
minWidth: 70.0,
),
height: 20.0,
width: 70.0,
decoration: BoxDecoration(
color: Colors.green[200],
borderRadius: BorderRadius.only(
topRight: Radius.circular(5.0),
bottomRight: Radius.circular(5.0),
)),
child: Center(
child: Text(
'status',
style: AppTheme(context).overLine().copyWith(fontFamily: 'ShabnamBold', color: Colors.black),
),
)),
),
],
),
onTap: () {},
),
),
Expanded(
child: ListView.builder(
itemBuilder: (context, index) {
return Card(
clipBehavior: Clip.antiAlias,
child: Padding(
padding: const EdgeInsets.all(20.0),
child: Column(
mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Row(
children: <Widget>[
Text(
ticketReplies[index].createdAt,
style: AppTheme(context).caption().copyWith(fontFamily: 'ShabnamLight'),
),
],
),
ListTile(
title: Text(ticketReplies[index].reply),
),
],
),
),
);
},
itemCount: ticketReplies.length,
),
),
],
);
} else {
return Center(
child: Text(
'there isn't any reply message',
style: AppTheme(context).caption(),
),
);
}
} else {
return _loader(context, 'no reply');
}
} else
return _loader(context, Strings.pleaseWait);
},
),
],
),
),
),
);
}
Widget _loader(BuildContext context,String message) {
return Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
ColorLoader3(
radius: 25.0,
dotRadius: 5.0,
),
Padding(
padding: const EdgeInsets.all(3.0),
child: Text(
Strings.pleaseWait,
style: AppTheme(context).caption().copyWith(color: Colors.red[900]),
),
),
],
));
}
}
Mon code:
The following assertion was thrown during performLayout(): I/flutter (13816): RenderFlex children have non-zero flex but incoming height constraints are unbounded. I/flutter (13816): When a column is in a parent that does not provide a finite height constraint, for example if it is I/flutter (13816): in a vertical scrollable, it will try to shrink-wrap its children along the vertical axis. Setting a I/flutter (13816): flex on a child (e.g. using Expanded) indicates that the child is to expand to fill the remaining I/flutter (13816): space in the vertical direction. I/flutter (13816): These two directives are mutually exclusive. If a parent is to shrink-wrap its child, the child I/flutter (13816): cannot simultaneously expand to fit its parent. I/flutter (13816): Consider setting mainAxisSize to MainAxisSize.min and using FlexFit.loose fits for the flexible I/flutter (13816): children (using Flexible rather than Expanded). This will allow the flexible children to size I/flutter (13816): themselves to less than the infinite remaining space they would otherwise be forced to take, and I/flutter (13816): then will cause the RenderFlex to shrink-wrap the children rather than expanding to fit the maximum I/flutter (13816): constraints provided by the parent. I/flutter (13816): If this message did not help you determine the problem, consider using debugDumpRenderTree():
3 Réponses :
Enveloppez votre Column dans une Expanded ou SizedBox (avec une certaine height ) comme ceci:
SizedBox( height: 200, // Some height child: Column(...), )
OU
Expanded( child: Column(...) )
A travaillé pour moi. Merci beaucoup!
Veuillez répondre pourquoi ce message d'erreur se produit? Quel est le sens?
@JoelGMathew Vous voudrez peut-être voir ce post
Essayez d'envelopper la Column ou tout autre widget dans Expanded ou Flexible et ce sera fait.
Et n'oubliez pas de donner de la hauteur aux Scrolling widgets
Le correctif pour ce problème ci-dessus consiste à envelopper le widget Column dans un widget Expanded . Exemple ci-dessous.
Expanded(
child: Column(
children: <Widget>[
Container(
height: 400,
width: 400,
child: ListView.builder(
itemCount: 2,
itemBuilder: (context, position) {
return Card(
child: Padding(
padding: const EdgeInsets.all(16.0),
child: Text("e.g., those that are not Expanded"),
),
);
},
),
),
],
),
)
Pour en savoir plus, consultez ceci: «Les enfants de RenderFlex ont un flex non nul».
Cette approche ne me manque jamais:
Card(
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Text("Lorem ipsum dolor sit amet, consectetur adipiscing elit. Phasellus finibus luctus tortor id pulvinar. Donec sollicitudin, dui vitae aliquam tristique, eros risus commodo enim, eget lobortis arcu velit ac arcu. "),
Text("Nunc tristique, ex ut volutpat feugiat, nulla nibh iaculis lectus, laoreet auctor justo tellus quis mi. Praesent ut interdum sem. Donec eget finibus augue, et vehicula elit. Praesent eu euismod arcu, eu maximus tellus. Ut diam est, sodales nec enim a, pharetra lobortis erat."),
]
)
)