-1
Hello, all the Listview of my application in Flutter if add more than 3 items occurs to Exception below:
I/flutter (13259): ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════ I/flutter (13259): The following assertion was thrown building I/flutter (13259): Rawgesturedetector-[Labeledglobalkey#fd1f4](state: I/flutter (13259): Rawgesturedetectorstate#a263f(Estures: , behavior: Paque)): I/flutter (13259): 'package:flutter/src/Rendering/sliver_multi_box_adaptor.Dart': Failed assertion: line 263 pos 16: I/flutter (13259): 'Child == null || indexof(Child) > index': is not true.
After this Exception, I try to go to another screen and the following error appears in my Listview, then expands to the whole screen!
I/flutter ( 7826): Another Exception was thrown: 'package:flutter/src/widgets/framework.Dart': Failed assertion: line 1772 pos 12: '_Elements.contains(element)': is not true.
Someone’s been through this and can help me?
Widget Code:
@override
void dispose() {
listViewController.removeListener(_scrollListener);
super.dispose();
}
@override
Widget build(BuildContext context) {
return Scaffold(
resizeToAvoidBottomPadding: true,
key: _scaffoldstate,
body: (_listaTela.length == 0)
? new AppLayout(
navBar: NavBar(
title: "$_titulo",
),
widget: Column(
//crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
Padding(
padding: const EdgeInsets.only(
top: 15.0,
),
child: Row(
children: <Widget>[
Padding(
padding: const EdgeInsets.only(left: 35.0, right: 15.0),
child: Container(
width: 45.0,
height: 45.0,
decoration: BoxDecoration(
border: Border.all(width: 1.0, color: Colors.grey),
shape: BoxShape.circle),
child: new Icon(Icons.shopping_basket)),
),
Text("$_titulo",
style: TextStyle(
fontSize: 16.0, fontWeight: FontWeight.w600))
],
),
),
Padding(
padding: const EdgeInsets.only(
left: 25.0, right: 25.0, top: 10.0, bottom: 15.0),
child: Divider(
height: 1.0,
),
),
// sem itens
Offstage(
offstage: !_semItens,
child: Column(
children: <Widget>[
Icon(
Icons.list,
size: 50.0,
),
Text('Sem itens'),
FlatButton(
onPressed: () {
_resetLista();
},
child: Text('Atualizar'),
)
],
),
),
// loading
Offstage(
offstage: !_ocupado,
child: Center(child: CircularProgressIndicator()),
),
],
),
)
: new AppLayout(
navBar: NavBar(
title: "$_titulo",
),
widget: Column(
//crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
Padding(
padding: const EdgeInsets.only(
top: 15.0,
),
child: Row(
children: <Widget>[
Padding(
padding: const EdgeInsets.only(left: 35.0, right: 15.0),
child: Container(
width: 45.0,
height: 45.0,
decoration: BoxDecoration(
border: Border.all(width: 1.0, color: Colors.grey),
shape: BoxShape.circle),
child: new Icon(Icons.shopping_basket)),
),
Text("$_titulo",
style: TextStyle(
fontSize: 16.0, fontWeight: FontWeight.w600))
],
),
),
Padding(
padding: const EdgeInsets.only(
left: 25.0, right: 25.0, top: 10.0, bottom: 15.0),
child: Divider(
height: 1.0,
),
),
// sem itens
Offstage(
offstage: !_semItens,
child: Column(
children: <Widget>[
Icon(
Icons.list,
size: 50.0,
),
Text('Sem itens'),
FlatButton(
onPressed: () {
_resetLista();
},
child: Text('Atualizar'),
)
],
),
),
// loading
Offstage(
Flexible(
child: ClipRect(
child: RefreshIndicator(
onRefresh: _resetLista,
child: ListView(
padding: const EdgeInsets.only(
left: 4.0,
right: 4.0,
),
controller: listViewController,
children: _listaTela.map((it) {
return Dismissible(
background: Container(color: Colors.red,),
key: ValueKey("remover"),
onDismissed: (direction){
setState((){
_removerItem(it);
});
},
child: ListTile(
onTap: () {
_itemSel(it, _listaTela.indexOf(it));
},
title: Row(
children: <Widget>[
Padding(
padding: EdgeInsets.only(right: 12.0),
child: Container(
height: 40.0,
width: 50.0,
child: Icon(
Icons.label,
color: Colors.white,
size: 30.0,
),
color: Colors.blueGrey,
)),
Flexible(
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Column(
crossAxisAlignment:
CrossAxisAlignment.start,
children: <Widget>[
Padding(
padding: const EdgeInsets.only(
bottom: 4.0),
child: Text(
it.produto.descricao.toString(),
textAlign: TextAlign.left,
style: TextStyle(
fontSize: 15.0,
letterSpacing: 1.0,
fontWeight: FontWeight.bold),
maxLines: 1,
overflow: TextOverflow.ellipsis,
),
),
Padding(
padding: const EdgeInsets.only(
bottom: 4.0),
child: Text(
it.quantidade.toString(),
textAlign: TextAlign.left,
style: TextStyle(
fontSize: 15.0,
letterSpacing: 1.0,
),
maxLines: 1,
overflow: TextOverflow.ellipsis,
),
),
],
),
],
),
),
],
),
)
);
}).toList()),
),
),
),
Padding(
padding: const EdgeInsets.only(bottom: 8.0),
child: Row(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Padding(
padding: const EdgeInsets.all(10.0),
child: Text(
'$_lblTot',
style: const TextStyle(color: Colors.grey),
),
),
],
),
),
],
),
),
floatingActionButton: SpeedDial(
animatedIcon: AnimatedIcons.menu_close,
children: [
SpeedDialChild(
child: Icon(Icons.add),
label: "Adicionar item",
onTap: () {
_add();
},
),
SpeedDialChild(
child: Icon(Icons.send),
label: "Enviar pedido",
backgroundColor: Colors.green,
onTap: () {
_enviar();
}
)
],
),
);
}
}
Show the code you made.
– robsonp
Without the code it’s not possible to analyze
– Julio Henrique Bitencourt
I’ve added the Listview code, thanks in advance.
– Dener Portela
It would be interesting an example that it was possible to reproduce, take your code and execute.. If it is not possible to pass, I would recommend removing Widget by Widget from the tree to identify where the problem is.
– Julio Henrique Bitencourt
@Juliohenriquebitencourt I will create a code that to reproduce, thank you.
– Dener Portela
@Denerportela show! It will facilitate the analysis.
– Julio Henrique Bitencourt
@Juliohenriquebitencourt I put the project on Github: https://github.com/denerportela/flutter_listview_bug_itens 1. Download the project. 2. Run. 3. Click the Floating Menu Button 4. Click the + After the 3rd click the error will appear!
– Dener Portela
If the answer helped/answered your question, mark it as accepted.
– Julio Henrique Bitencourt