web-app tutorial missing line

Francesco Gurrieri

unread,

Apr 24, 2020, 6:16:37 AM4/24/20

to Flutter Development (flutter-dev)

Hi,

I am completely new to flutter and relatively new to web design, so it's possible I am missing something.

However,

Doing the tutorial until the end of step 1 at https://flutter.dev/docs/get-started/codelab-web

I found this error when pressing the button:

════════ Exception caught by gesture ═══════════════════════════════════════════

Could not find a generator for route RouteSettings("/welcome", null) in the _WidgetsAppState.

I solved it by modifying routed in the LoginApp widget

class LoginApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      routes: {
        '/': (context) => LoginScreen(),
        '/welcome': (context) => WelcomeScreen(), // Added this line to fix the issue
      },
    );
  }
}

In case I am right it may be worth to update tutorial

Regards,

Francesco

Souvik Dutta

unread,

Apr 24, 2020, 6:41:22 AM4/24/20

to Francesco Gurrieri, Flutter Development (flutter-dev)

Post your whole code. This happened with me and I understood it was a spelling mistake.

Souvik flutter dev

--
You received this message because you are subscribed to the Google Groups "Flutter Development (flutter-dev)" group.
To unsubscribe from this group and stop receiving emails from it, send an email to flutter-dev...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/flutter-dev/26b1eea6-5e5f-42c5-b20f-57a83b703758%40googlegroups.com.

Francesco Gurrieri

unread,

Apr 24, 2020, 6:46:42 AM4/24/20

to Flutter Development (flutter-dev)

Thanks for your reply!

This is my whole main.dart:

import 'package:flutter/material.dart';

void main() => runApp(LoginApp());


class LoginApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      routes: {
        '/': (context) => LoginScreen(),
        '/welcome': (context) => WelcomeScreen(), // Added this line to fix the issue
      },
    );
  }
}

class WelcomeScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Text('Welcome!', style: Theme.of(context).textTheme.display3),
      ),
    );
  }
}

class LoginScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.grey[200],
      body: Center(
        child: SizedBox(
          width: 400,
          child: Card(
            child: LoginForm(),
          ),
        ),
      ),
    );
  }
}

class LoginForm extends StatefulWidget {
  @override
  _LoginFormState createState() => _LoginFormState();
}

class _LoginFormState extends State<LoginForm> {
  final _firstNameTextController = TextEditingController();
  final _lastNameTextController = TextEditingController();
  final _usernameTextController = TextEditingController();

  double _formProgress = 0;
  void _showWelcomeScreen() {
    Navigator.of(context).pushNamed('/welcome');
  }

  @override
  Widget build(BuildContext context) {
    return Form(
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          LinearProgressIndicator(value: _formProgress),
          Text('Sign Up', style: Theme
              .of(context)
              .textTheme
              .display1), // display1 changes to headline4 in 1.16
          Padding(
            padding: EdgeInsets.all(8.0),
            child: TextFormField(
              controller: _firstNameTextController,
              decoration: InputDecoration(hintText: 'First name'),
            ),
          ),
          Padding(
            padding: EdgeInsets.all(8.0),
            child: TextFormField(
              controller: _lastNameTextController,
              decoration: InputDecoration(hintText: 'Last name'),
            ),
          ),
          Padding(
            padding: EdgeInsets.all(8.0),
            child: TextFormField(
              controller: _usernameTextController,
              decoration: InputDecoration(hintText: 'Username'),
            ),
          ),
          FlatButton(
            color: Colors.blue,
            textColor: Colors.white,
            onPressed:  _showWelcomeScreen,
            child: Text('Sign up'),
          ),
        ],
      ),
    );
  }
}

To unsubscribe from this group and stop receiving emails from it, send an email to flutt...@googlegroups.com.

Reply all

Reply to author

Forward