How do i remove range error running in flutter? - flutter

Question

I have created a string List and applied a checkbox and when the checkbox clicked, the string list will be shown on the next screen but I am getting a range error. please help.
var _suggestions = <String>['this is me1','this is me2','this is me3' ];
final _saved = <String>['this is me1','this is me2','this is me3' ];
final _biggerFont = TextStyle(fontSize: 18.0);
this is the string that I have defined.
void _pushSaved(){
Navigator.of(context).push(
MaterialPageRoute<void>(
// NEW lines from here...
builder: (BuildContext context) {
final tiles = _saved.map(
(String pair) {
return ListTile(
title: Text(
pair,
style: _biggerFont,
),
);
},
);
final divided = ListTile.divideTiles(
context: context,
tiles: tiles,
).toList();
return Scaffold(
appBar: AppBar(
title: Text('Saved Suggestions'),
),
body: ListView(children: divided),
);
}, // ...to here.
),
);
}
this is some page route
Widget _buildSuggestions() {
return ListView.builder(
padding: EdgeInsets.all(16.0),
itemBuilder: /*1*/ (context, i) {
if (i.isOdd) return Divider(); /*2*/
final index = i ~/ 2; /*3*/
_suggestions = <String>['this is me1','this is me2','this is me3'];
return _buildRow(_suggestions[index]);
});
}
There is no problem in showing selected checkbox data into the next screen but I don't know why the range error is showing.
Widget _buildRow(String pair) {
final alreadySaved = _saved.contains(pair);
return Container(
decoration: new BoxDecoration (
color: HexColor('#F2FFFF'),
border: Border.all(color: HexColor('#09B9B6')),
borderRadius: BorderRadius.all(Radius.circular(20)),
),
child: ListTile(
title: Text(
pair,
style: _biggerFont,
),
trailing: Icon(
alreadySaved ? Icons.check_box : Icons.check_box_outline_blank_outlined,
color: alreadySaved ? HexColor('#09B9B6') :null,
),
onTap: (){
setState(() {
if (alreadySaved){
_saved.remove(pair);
}
else{
_saved.add(pair);
}
});
},
),
);
}
this is the build row function

Answer 1

We can also use ListView.separated
ListView.separated(
padding: EdgeInsets.all(16.0),
itemBuilder: (context, index) {
return _buildRow(_suggestions[index]);
},
separatorBuilder: (_, __) => Divider(),
itemCount: _suggestions.length);