함수를 생성자로 전달하기(부제 : double.parse)

import 'package:flutter/material.dart';
import './new_transaction.dart';
import './transaction_list.dart';
import '../models/transaction.dart';

class UserTransaction extends StatefulWidget {
  const UserTransaction({super.key});

  @override
  State<UserTransaction> createState() => _UserTransactionState();
}

class _UserTransactionState extends State<UserTransaction> {
  final List<Transaction> _userTransaction = [
    Transaction(
        id: 't1', title: 'new shoes', amount: 69.99, date: DateTime.now()),
    Transaction(
        id: 't2',
        title: 'weekly groceries',
        amount: 16.53,
        date: DateTime.now())
  ];
  
  ////////////////함수로 전달하기////////////////////
  void _addNewTransaction(String txTitle, double txAmount) {
    final newTx = Transaction(
        title: txTitle,
        amount: txAmount,
        date: DateTime.now(),
        id: DateTime.now().toString());
    setState(() {
      _userTransaction.add(newTx);
    });
  }
  ////////////////////////////////////////////////////////////

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        NewTransaction(_addNewTransaction),//함수의 주소값을 전달
        TransactionList(_userTransaction),
      ],
    );
  }
}

import 'package:flutter/material.dart';

class NewTransaction extends StatelessWidget {
  // NewTransaction({super.key, this.addTx});
  final Function? addTx; //Function 데이터형
  final titleController = TextEditingController();
  final amountController = TextEditingController();
  NewTransaction(this.addTx);
  @override
  Widget build(BuildContext context) {
    return Card(
      elevation: 5,
      child: Container(
        padding: EdgeInsets.all(10),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.end,
          children: [
            TextField(
              decoration: InputDecoration(labelText: 'Title'),
              // onChanged: (value) {
              //   titleInput = value;
              // },
              controller: titleController,
            ),
            TextField(
              decoration: InputDecoration(labelText: 'Amount'),
              // onChanged: (value) => amountInput = value,
              controller: amountController,
            ),
            TextButton(
              onPressed: () {
              //전달받은 함수에 파라미터 넣기
              //duble.parse(amountController.text) ->string를 double형으로 변환
                addTx!(titleController.text, duble.parse(amountController.text));
              },
              child: Text(
                'Add Transaction',
                style: TextStyle(color: Colors.purple),
              ),
            ),
          ],
        ),
      ),
    );
  }
}