Multiple TextEditingController

main.dart

import 'package:flutter/material.dart';

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

void main() {
  runApp(MaterialApp(
    theme: ThemeData.dark().copyWith(
      scaffoldBackgroundColor: darkBlue,
    ),
    debugShowCheckedModeBanner: false,
    home: ListData(),
  ));
}

class ListData extends StatefulWidget {
  @override
  _ListDataState createState() => _ListDataState();
}

class _ListDataState extends State<ListData> {
  final List<List<String>> dataList = [
    <String>['Rose', 'SunFlower'],
    <String>['SUV', 'CityCar', 'Jeep'],
  ];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Data List'),
      ),
      body: ListView(
        children: ListTile.divideTiles(
          context: context,
          tiles: dataList.map(
            (list) {
              return ListTile(
                  leading: CircleAvatar(
                    child: Text('${list.length}'),
                  ),
                  title: Text(list.join(', ')),
                  onTap: () async {
                    final editData = await Navigator.push(
                      context,
                      MaterialPageRoute(
                        builder: (context) => Form(data: list),
                        fullscreenDialog: true,
                      ),
                    );

                    if (editData != null) {
                      final index = dataList.indexOf(list);

                      if (index != -1) {
                        setState(() {
                          dataList[index] = editData;
                        });
                      }
                    }
                  });
            },
          ),
        ).toList(),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () async {
          final newData = await Navigator.push(
            context,
            MaterialPageRoute(
              builder: (context) => Form(),
              fullscreenDialog: true,
            ),
          );

          if (newData != null) {
            setState(() {
              dataList.add(newData);
            });
          }
        },
        child: Icon(Icons.add),
      ),
    );
  }
}

class Form extends StatefulWidget {
  final List<String> data;

  Form({List<String> data}) : data = data ?? <String>[];

  @override
  _FormState createState() => _FormState();
}

class _FormState extends State<Form> {
  List<TextEditingController> controllers;

  @override
  void initState() {
    super.initState();

    setState(() {
      if (widget.data.isNotEmpty) {
        controllers = widget.data.map((s) {
          return TextEditingController(text: s);
        }).toList();
      } else {
        controllers = [];
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('Form'), actions: [
        IconButton(
          icon: Icon(Icons.save),
          onPressed: () {
            if (controllers.isEmpty) {
              print('Data is empty, cannot saved');
              return;
            }

            final list = controllers.map((c) => c.text).toList();
            Navigator.pop(context, list);
          },
        ),
      ]),
      body: controllers == null
          ? CircularProgressIndicator()
          : ListView(
              children: controllers.map((controller) {
                return Container(
                  padding: const EdgeInsets.all(16),
                  child: TextField(
                    controller: controller,
                    decoration: InputDecoration(
                      labelText:
                          'Type data index-${controllers.indexOf(controller) + 1}',
                    ),
                  ),
                );
              }).toList(),
            ),
      floatingActionButton: Row(
        mainAxisSize: MainAxisSize.min,
        children: [
          FloatingActionButton(
            heroTag: 'min',
            onPressed: () {
              setState(() {
                controllers.removeLast();
              });
            },
            child: Icon(Icons.remove),
          ),
          SizedBox(width: 8),
          FloatingActionButton(
            heroTag: 'add',
            onPressed: () {
              setState(() {
                controllers.add(TextEditingController());
              });
            },
            child: Icon(Icons.add),
          )
        ],
      ),
    );
  }
}