格式异常错误 Double INVALID IN New-Transaction 类

Question

当输入字段中的供应值加倍并点击按钮添加新交易时，它会给我错误异常发生双倍无效

这个项目的想法是这是一个关于费用用户提供两个值项目名称和价格的项目项目，该项目将添加到列表中并在屏幕上显示为列表一切正常，但只有一个错误或异常

import 'package:flutter/material.dart';

class NewTransaction extends StatelessWidget {
  //NewTransaction({Key? key}) : super(key: key);

  //@override
  //State<NewTransaction> createState() => _NewTransactionState();
  final Function addTx;
  final titleController = TextEditingController();
  final amountController = TextEditingController();
  NewTransaction(this.addTx, {Key? key}) : super(key: key);
  @override
  Widget build(BuildContext context) {
    return Card(
      elevation: 10,
      child: Container(
        padding: const EdgeInsets.all(10),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.end,
          children: [
            TextField(
              decoration: const InputDecoration(
                  labelText: 'Enter Title',
                  labelStyle: TextStyle(
                    fontSize: 25,
                  )),
              // onChanged: (value) {
              //   inputtitle = value;
              // },
              controller: titleController,
            ),
            TextField(
              decoration: const InputDecoration(
                  labelText: 'Enter Amount',
                  labelStyle: TextStyle(fontSize: 25)),
              //One of this method to save value in a field but we try another method
              // onChanged: (value) {
              //   inputamount = value;
              // },
              controller: amountController,
            ),
            TextButton(
                onPressed: () {
                  //using lisnter mentod i confirm this way my value is save or not
                  // print(inputtitle);
                  // print(inputamount);
                  // print(titleController.text);
                  addTx(
                    titleController.text,
                    double.parse(amountController.text),
                  );
                },
                child: Text('Add Transaction',
                    style: TextStyle(color: Colors.purple)))
          ],
        ),
      ),
    );
  }
}

格式异常错误：无效双精度

用户事务类

import 'package:flutter/widgets.dart';
import '../modals/transactions.dart';
import 'new_transaction.dart';
import 'transaction_list.dart';

class UserTransactions extends StatefulWidget {
  const UserTransactions({Key? key}) : super(key: key);

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

class _UserTransactionsState extends State<UserTransactions> {
  final List<TranSaction> _userTransactions = [
    TranSaction(
      id: 't1',
      title: 'New Shoes',
      amount: 69.99,
      date: DateTime.now(),
    ),
    TranSaction(
      id: 't2',
      title: 'Weekly Groceries',
      amount: 16.53,
      date: DateTime.now(),
    ),
  ];

  void _addNewTransaction(String txTitle, double txAmount) {
    final newTx = TranSaction(
      title: txTitle,
      amount: txAmount,
      date: DateTime.now(),
      id: DateTime.now().toString(),
    );

    setState(() {
      _userTransactions.add(newTx);
    });
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children: <Widget>[
        NewTransaction(_addNewTransaction),
        TransactionList(_userTransactions),
      ],
    );
  }
}

import 'package:budget/modals/transactions.dart';
import 'package:flutter/material.dart';
import 'package:intl/intl.dart';

class TransactionList extends StatefulWidget {
  const TransactionList(List<TranSaction> userTransactions, {Key? key})
      : super(key: key);

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

class _TransactionListState extends State<TransactionList> {
  final List<TranSaction> _userTransacton = [
    TranSaction(
        id: 't1', title: 'New Shoes', amount: 69.9, date: DateTime.now()),
    TranSaction(
        id: 't2',
        title: 'Weekly Groceries',
        amount: 16.53,
        date: DateTime.now())
  ];
  @override
  Widget build(BuildContext context) {
    return Column(
      children: _userTransacton.map(
        (tx) {
          return Card(
              child: Row(
            children: [
              Container(
                margin:
                    const EdgeInsets.symmetric(vertical: 20, horizontal: 30),
                decoration: BoxDecoration(
                    border: Border.all(color: Colors.purple, width: 2)),
                padding: const EdgeInsets.all(10),
                child: Text(
                  //we use here string interpolation to output dollor sign
                  '\$${tx.amount}',
                  style: TextStyle(
                      fontWeight: FontWeight.bold,
                      color: Colors.purple,
                      fontSize: 25),
                ),
              ),
              Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    tx.title,
                    style: TextStyle(fontWeight: FontWeight.bold, fontSize: 20),
                  ),
                  SizedBox(
                    height: 10,
                  ),
                  Text(
                    DateFormat('y/m/d').format(tx.date),
                    style: TextStyle(color: Colors.blueGrey, fontSize: 15),
                  )
                ],
              )
            ],
          ));
        },
      ).toList(),
    );
  }
}

class TranSaction {
  final String id;
  final String title;
  final double amount;
  final DateTime date;
  TranSaction(
      {required this.id,
      required this.title,
      required this.amount,
      required this.date});
}