How to solve this error of AlertDialog in Flutter

August 19, 2023

I’m trying to get the result of this code. I want to show a Confirm AlertDialog with two buttons, One Accepting and Other One Cancelling and want display the result of pressing each button in the debug console. I have read the documentation related to this error but couldn’t find anything helpful.
You can see the error is in first Image.

This is my Code

import 'dart:async';
import 'package:flutter/material.dart';

class dayThirteen extends StatelessWidget {
  const dayThirteen({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: AlertWidget(),
    );
  }
}

class AlertWidget extends StatelessWidget {
  AlertWidget({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Day Thirteen (Alert Widget)'),
      ),
      body: Center(
        child: Container(
          child: ElevatedButton(
              style: ElevatedButton.styleFrom(backgroundColor: Colors.blue),
              onPressed: () async {

                final field fieldatt = await confirmalertdialogwidget(context);
                print("User Selection $fieldatt");
              },
              child: Text('Basic AlertDialog')),
        ),
      ),
    );
  }
}

enum field { Confirm, Accept }
Future<field> confirmalertdialogwidget(BuildContext context) async{
  showDialog<field>(
      barrierDismissible: true,
      context: context,
      builder: (BuildContext context) {
        return AlertDialog(
          title: Text('Confirm'),
          content: Text('This is for notification purpose!!!!'),
          actions: [
            ElevatedButton(
                style: ElevatedButton.styleFrom(backgroundColor: Colors.red),
                onPressed: () {
                  Navigator.of(context).pop(field.Confirm);
                },
                child: Text("Cancel")),
            ElevatedButton(
              onPressed: () {
                Navigator.of(context).pop(field.Accept);
              },
              child: Text('Accept'),
              style: ElevatedButton.styleFrom(backgroundColor: Colors.blue),
            )
          ],
        );
      });
}

Error in Code
Error Message

>Solution :

You are not returning the Futrue from the method, and the dialog can be dismissed (Thus, the return is optional):

Future<field?> confirmalertdialogwidget(BuildContext context) async{
  return showDialog<field>(
      barrierDismissible: true,
      context: context,
      builder: (BuildContext context) {
        return AlertDialog(
          title: Text('Confirm'),
          content: Text('This is for notification purpose!!!!'),
          actions: [
            ElevatedButton(
                style: ElevatedButton.styleFrom(backgroundColor: Colors.red),
                onPressed: () {
                  Navigator.of(context).pop(field.Confirm);
                },
                child: Text("Cancel")),
            ElevatedButton(
              onPressed: () {
                Navigator.of(context).pop(field.Accept);
              },
              child: Text('Accept'),
              style: ElevatedButton.styleFrom(backgroundColor: Colors.blue),
            )
          ],
        );
      },
  );
}

You need to consider naming the Enum and the method based on Dart naming convention