Flutter how to add items in list - flutter

Question

Here is my code
class _VariantsState extends State<Variants> {
List<VariantDetails> variantsList = [];
#override
void initState() {
super.initState();
variantsList.clear();
}
return Card(
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(5.0),
),
color: Colors.white,
elevation: 5,
margin:
EdgeInsets.only(top: 40.0, bottom: 40.0, left: 20.0, right: 20.0),
child: SingleChildScrollView(
child: Column(
children: <Widget>[
Padding(
padding: EdgeInsets.only(
top: 10, bottom: 5.0, left: 20.0, right: 20.0),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
Text(
'Variants',
style: TextStyle(
fontWeight: FontWeight.bold, color: Colors.black),
),
IconButton(
onPressed: () {
setUpData();
showModalBottomSheet(
isScrollControlled: true,
context: context,
builder: (BuildContext context) {
return SingleChildScrollView(
child: Container(
color: Colors.white,
margin: EdgeInsets.all(10.0),
child: Flexible(
child: Padding(
padding: EdgeInsets.only(
left: 10.0, right: 10.0),
child: Column(
crossAxisAlignment:
CrossAxisAlignment.stretch,
mainAxisSize: MainAxisSize.max,
mainAxisAlignment:
MainAxisAlignment.start,
children: <Widget>[
Row(
children: <Widget>[
Image.asset(
'assets/svg/barcode_reader.png',
height: 20.0,
width: 20.0,
),
Padding(
padding: EdgeInsets.only(
left: 20.0)),
Text(
'Add Goods',
style: TextStyle(
fontWeight: FontWeight.bold,
color: Colors.black,
fontSize: 17.0),
)
],
),
Form(
key: _formKey,
child: Column(
children: <Widget>[
Padding(
padding: EdgeInsets.only(
bottom: 20.0,
top: 40.0,
),
child: TextFormField(
// initialValue:
// variantDetails.name,
validator: (value) {
if (value
.trim()
.isEmpty) {
return 'Enter Name';
}
return null;
},
onChanged: (value) =>
variantDetails.name =
value,
decoration:
InputDecoration(
border:
OutlineInputBorder(),
hintText: 'Name',
hintStyle: TextStyle(
fontSize: 13.0),
hintMaxLines: 1,
contentPadding:
EdgeInsets.fromLTRB(
20.0,
8.0,
20.0,
8.0),
),
),
),
Padding(
padding: EdgeInsets.only(
bottom: 10.0,
),
child: TextFormField(
// initialValue:
// variantDetails
// .description,
onChanged: (value) =>
variantDetails
.description =
value,
validator: (value) {
if (value
.trim()
.isEmpty) {
return 'Enter Description';
}
return null;
},
decoration:
InputDecoration(
border:
OutlineInputBorder(),
hintText: 'Description',
hintStyle: TextStyle(
fontSize: 13.0),
hintMaxLines: 1,
contentPadding:
EdgeInsets.fromLTRB(
20.0,
15.0,
20.0,
15.0),
),
),
),
Row(
mainAxisAlignment:
MainAxisAlignment
.spaceAround,
children: <Widget>[
Expanded(
child: TextFormField(
// initialValue:
// variantDetails
// .price,
onChanged: (value) =>
variantDetails
.price =
value,
validator: (value) {
if (value
.trim()
.isEmpty) {
return 'Enter Price';
}
return null;
},
keyboardType:
TextInputType
.phone,
decoration:
InputDecoration(
border:
OutlineInputBorder(),
hintText: 'Price',
hintStyle:
TextStyle(
fontSize:
13.0),
hintMaxLines: 1,
contentPadding:
EdgeInsets
.fromLTRB(
20.0,
15.0,
20.0,
15.0),
),
),
),
Padding(
padding:
EdgeInsets.only(
left: 10.0)),
Expanded(
child: TextFormField(
// initialValue:
// variantDetails
// .nonTax,
decoration:
InputDecoration(
border:
OutlineInputBorder(),
hintText:
'Inclusive of GST',
hintStyle:
TextStyle(
fontSize:
13.0),
hintMaxLines: 1,
suffixIcon: Icon(Icons
.arrow_drop_down),
contentPadding:
EdgeInsets
.fromLTRB(
20.0,
15.0,
20.0,
15.0),
),
),
)
],
),
],
)),
Padding(
padding:
EdgeInsets.only(top: 10.0)),
Row(
mainAxisAlignment:
MainAxisAlignment.spaceBetween,
children: <Widget>[
Text(
'Net Price',
style: TextStyle(
fontWeight: FontWeight.bold,
color: Colors.black,
fontSize: 17.0),
),
Text(
'0',
style: TextStyle(
fontWeight: FontWeight.bold,
color: Colors.black,
fontSize: 17.0),
)
],
),
Padding(
padding:
EdgeInsets.only(top: 10.0)),
Row(
mainAxisAlignment:
MainAxisAlignment.spaceBetween,
children: <Widget>[
Text(
'Total',
style: TextStyle(
fontWeight: FontWeight.bold,
color: Colors.black,
fontSize: 17.0),
),
Text(
'0',
style: TextStyle(
fontWeight: FontWeight.bold,
color: Colors.black,
fontSize: 17.0),
)
],
),
Padding(
padding:
EdgeInsets.only(top: 10.0)),
ElevatedButton(
onPressed: () {
trySubmit(context);
},
child: Text('UPDATE'))
],
),
),
),
));
});
},
icon: Icon(Icons.add_circle_outline)),
],
),
),
Visibility(
visible: isVisible,
child: new ListView.builder(
shrinkWrap: true,
itemBuilder: (BuildContext context, int index) {
return new ExpandableListView('Variant $index', ItemList);
},
itemCount: variantsList.length,
),
)
],
),
));
//Here is the expandable list where i am showing my listview
class ExpandableListView extends StatefulWidget {
final String title;
final List<VariantDetails> variantList;
ExpandableListView(this.title, this.variantList);
#override
_ExpandableListViewState createState() =>
new _ExpandableListViewState(this.title, this.variantList);
}
class _ExpandableListViewState extends State<ExpandableListView> {
bool expandFlag = false;
final String title;
final List<VariantDetails> variantList;
_ExpandableListViewState(this.title, this.variantList);
#override
Widget build(BuildContext context) {
return new Container(
margin: new EdgeInsets.symmetric(vertical: 1.0),
child: new Column(
children: <Widget>[
new Container(
color: Colors.white,
padding: new EdgeInsets.symmetric(horizontal: 20.0),
child: new Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
new Text(
widget.title,
style: new TextStyle(
fontWeight: FontWeight.bold, color: Colors.black),
),
new IconButton(
icon: new Container(
height: 20.0,
width: 20.0,
child: new Center(
child: new Icon(
expandFlag
? Icons.keyboard_arrow_up
: Icons.keyboard_arrow_down,
color: Colors.black,
size: 30.0,
),
),
),
onPressed: () {
setState(() {
expandFlag = !expandFlag;
});
}),
],
),
),
new ExpandableContainer(
expanded: expandFlag,
child: new ListView.builder(
itemBuilder: (BuildContext context, int index) {
return new Container(
child: Padding(
padding:
EdgeInsets.only(left: 20.0, right: 20.0, top: 10.0),
child: Column(
children: <Widget>[
Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
crossAxisAlignment: CrossAxisAlignment.center,
mainAxisSize: MainAxisSize.max,
children: <Widget>[
Text(
'Edit Variants',
style: TextStyle(
fontSize: ScreenUtil().setSp(14),
fontFamily: 'poppins',
color: Colors.black),
),
Row(
children: <Widget>[
IconButton(
onPressed: () {
// Dismissible(key: Key(variantList[index]), child: child)
},
icon: Icon(Icons.delete)),
Icon(Icons.edit),
],
)
],
),
Padding(padding: EdgeInsets.only(top: 20)),
Row(
// mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Text('Name',
style: new TextStyle(
fontFamily: 'poppins',
fontSize: ScreenUtil().setSp(12),
color: Colors.black)),
Text('Price',
style: new TextStyle(
fontFamily: 'poppins',
fontSize: ScreenUtil().setSp(12),
color: Colors.black)),
Text('Description',
style: new TextStyle(
fontFamily: 'poppins',
fontSize: ScreenUtil().setSp(12),
color: Colors.black)),
Text('Price Type',
style: new TextStyle(
fontFamily: 'poppins',
fontSize: ScreenUtil().setSp(12),
color: Colors.black)),
Text('Non-taxable',
style: new TextStyle(
fontFamily: 'poppins',
fontSize: ScreenUtil().setSp(12),
color: Colors.black)),
Text('Code Type',
style: new TextStyle(
fontFamily: 'poppins',
fontSize: ScreenUtil().setSp(12),
color: Colors.black)),
Text('Stock Keeping Unit',
style: new TextStyle(
fontFamily: 'poppins',
fontSize: ScreenUtil().setSp(12),
color: Colors.black)),
Text('Net Price',
style: new TextStyle(
fontFamily: 'poppins',
fontSize: ScreenUtil().setSp(12),
color: Colors.black)),
Text('Tax',
style: new TextStyle(
fontFamily: 'poppins',
fontSize: ScreenUtil().setSp(12),
color: Colors.black)),
],
),
Expanded(
child: Column(
crossAxisAlignment: CrossAxisAlignment.center,
children: [
Text(variantList[index].description),
Text(variantList[index].description),
Text(variantList[index].description),
Text(variantList[index].description),
Text(variantList[index].description),
Text(variantList[index].description),
Text(variantList[index].description),
Text(variantList[index].description),
Text(variantList[index].description),
],
))
],
),
],
),
));
},
itemCount: variantList.length,
))
],
),
);
}
}
I am implementing listview in my flutter application and whenever i add items in variantsList the new added item is reflecting in all the index of a list.
for example i am adding A
variantsList[0]='A'
Now i am adding another value B
The result which i am getting is
variantsList[0]='B',
variantsList[1]='B',
Expecting result
variantsList[0]='A',
variantsList[1]='B',
Thanks in advance

Answer 1

According to my understanding, you mean deleting similar list data?
you have two way:-
check data befor add to list if found use :-
if(!variantsList.contains('B'))
{//not found add data to list
variantsList.add('B');
}
2.Use end result toSet and then toList
variantsList = variantsList.toSet().toList();
Hope hlep you.