textediting_controllers

import 'package:flutter/material.dart';

const Color darkBlue = Color.fromARGB(255, 18, 32, 47);

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: Center(
          child: MyWidget(),
        ),
      ),
    );
  }
}

class MyWidget extends StatelessWidget {
  
  List<String> _brandnames = ['Toyota', 'Honda', 'BMW', 'Mercedes'];
  List<TextEditingController> controllers = [];
  
  @override
  Widget build(BuildContext context) {
    
    controllers = [];
    
    return Column(
      children: [
        Expanded(
          child:  Container(
            child: ListView.builder(
              itemCount: _brandnames.length,
              itemBuilder: (BuildContext ctx, int index) {
                TextEditingController ctrl = TextEditingController();
                controllers.add(ctrl);
                return BrandNamesWidget(
                  brandName: _brandnames[index].toString(),
                  controller: ctrl,
                  index: index);
              }),
          )
        ),
        TextButton(
          onPressed: () {
            
            for(var ctrl in controllers) {
              print(ctrl.text);
            }
          },
          child: Text('Click me to get their values')
        )
      ]
    );
  }
}


class BrandNamesWidget extends StatelessWidget {
  
  final TextEditingController? controller;
  final String? brandName;
  final int? index;
  
  BrandNamesWidget({ this.brandName, required this.index, this.controller });
  
  @override
  Widget build(BuildContext context) {
    
    double height = 100;
    double width = MediaQuery.of(context).size.width;
    
    return TextField(
      controller: controller!,
      keyboardType: TextInputType.text,
      decoration: InputDecoration(
        constraints: BoxConstraints(maxWidth: width * 0.45),
        labelText: 'Brand name: ' + index.toString(),
        prefixIcon: const Icon(Icons.medication),
        labelStyle: TextStyle(
          fontSize: height * 0.03,
          color: Colors.grey,
        ),
        border: OutlineInputBorder(
          borderRadius: BorderRadius.circular(50),
        ),
      ),
    );
  }
}