How to return data from Flutter dialog? - flutter

Question

I'm having a dialog which opens up when click of a button and having a Listtile which Radio as a child in order to make a selection. As the user makes the selection and accepts it, I'm trying to update the selected part in the UI but i'm getting a null response while the value is being returned.
This is my custom statefull dialog
class _CustomScannerSelectDialogState extends State<CustomScannerSelectDialog> {
int selectedRadio;
setSelectedRadio(int val) {
setState(() {
selectedRadio = val;
});
}
#override
Widget build(BuildContext context) {
return Expanded(
child: Dialog(
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(20),
),
elevation: 0,
backgroundColor: Colors.transparent,
child: Stack(
children: [
Container(
padding: EdgeInsets.only(left: 20, top: 40, right: 20, bottom: 20),
margin: EdgeInsets.only(top: 40),
decoration: BoxDecoration(
shape: BoxShape.rectangle,
color: Colors.white,
borderRadius: BorderRadius.circular(20),
boxShadow: [
BoxShadow(color: Colors.black, offset: Offset(0, 10), blurRadius: 10),
]),
child: Column(
mainAxisSize: MainAxisSize.min,
children: [
SizedBox(
height: 20,
),
Text(
'Select the Scanner type',
style: TextStyle(fontSize: 20, fontWeight: FontWeight.w600),
),
SizedBox(
height: 15,
),
ListTile(
title: const Text('QR & Barcode scanner'),
leading: Radio(
activeColor: Color(0xFFCC0000),
value: 1,
groupValue: selectedRadio,
onChanged: (val) {
print("Radio $val");
setSelectedRadio(val);
},
),
),
ListTile(
title: const Text('Barras Scanner'),
leading: Radio(
activeColor: Color(0xFFCC0000),
value: 2,
groupValue: selectedRadio,
onChanged: (val) {
print("Radio $val");
setSelectedRadio(val);
},
),
),
SizedBox(
height: 20,
),
Row(
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: [
CustomButton(
buttonText: 'CANCEL',
buttonFunction: () {
Navigator.pop(context);
return;
},
),
RaisedButton(
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(10), side: BorderSide(color: Colors.blueGrey)),
textColor: Color(0xFFCD853F),
color: Colors.white,
onPressed: () {
print("Selected radio is " + selectedRadio.toString());
Navigator.pop(context);
return selectedRadio.toString();
},
child: new Text(
'ACCEPT',
),
)
],
),
],
),
),
],
),
));
}
}
And on click of a button I'm calling a function as _showScannerSelectionDialog
_showScannerSelectionDialog() {
showDialog(
context: context,
builder: (BuildContext context) {
return CustomScannerSelectDialog();
},
).then((value) => print("Value is "+value.toString()));
}
Here the value I'm getting printed is null but i need the value of the selectedRadio

Answer 1

I think, you only need to simply use the following when closing the dialog:
var result = selectedRadio.toString(); // or any value.
Navigator.pop(context, result);