Add date time of build/run to title text in Flutter app - flutter

Question

My current code in lib/main.dart looks like this:
import 'dart:math';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_form_bloc/flutter_form_bloc.dart';
void main() => runApp(const App());
class App extends StatelessWidget {
const App({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return const MaterialApp(
home: LoginForm(),
);
}
}
class CustomFieldBlocValidators implements FieldBlocValidators {
CustomFieldBlocValidators._();
static String? number(dynamic value) {
if (kDebugMode) {
print(value);
print(value is num);
}
if (value == null || value == false || num.tryParse(value) == null) {
return "Number input is required";
}
return null;
}
}
class LoginFormBloc extends FormBloc<String, String> {
final num1 = TextFieldBloc(
validators: [
FieldBlocValidators.required,
CustomFieldBlocValidators.number
],
);
final num2 = TextFieldBloc(
validators: [
FieldBlocValidators.required,
CustomFieldBlocValidators.number
],
);
LoginFormBloc() {
addFieldBlocs(
fieldBlocs: [
num1,
num2,
],
);
}
#override
void onSubmitting() async {
if (kDebugMode) {
print(DateTime.now());
print(num1.value);
print(num2.value);
}
await Future<void>.delayed(const Duration(seconds: 1));
if (Random().nextDouble() > 0.5) {
emitSuccess();
} else {
emitFailure(failureResponse: 'This is an awesome error!');
}
}
}
class LoginForm extends StatelessWidget {
const LoginForm({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return BlocProvider(
create: (context) => LoginFormBloc(),
child: Builder(
builder: (context) {
final loginFormBloc = context.read<LoginFormBloc>();
return Scaffold(
resizeToAvoidBottomInset: false,
appBar: AppBar(title: const Text('Basic Calculator - ')),
body: FormBlocListener<LoginFormBloc, String, String>(
onSubmitting: (context, state) {
LoadingDialog.show(context);
},
onSuccess: (context, state) {
LoadingDialog.hide(context);
Navigator.of(context).pushReplacement(
MaterialPageRoute(builder: (_) => const SuccessScreen()));
},
onFailure: (context, state) {
LoadingDialog.hide(context);
ScaffoldMessenger.of(context).showSnackBar(
SnackBar(content: Text(state.failureResponse!)));
},
child: SingleChildScrollView(
physics: const ClampingScrollPhysics(),
child: AutofillGroup(
child: Column(
children: <Widget>[
TextFieldBlocBuilder(
textFieldBloc: loginFormBloc.num1,
keyboardType: TextInputType.number,
decoration: const InputDecoration(
labelText: 'Number 1',
prefixIcon: Icon(Icons.dialpad),
),
),
TextFieldBlocBuilder(
textFieldBloc: loginFormBloc.num2,
keyboardType: TextInputType.number,
decoration: const InputDecoration(
labelText: 'Number 2',
prefixIcon: Icon(Icons.dialpad),
),
),
Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
ElevatedButton(
onPressed: loginFormBloc.submit,
child: const Text('ADD'),
),
ElevatedButton(
onPressed: loginFormBloc.submit,
child: const Text('SUBTRACT'),
),
],
)
],
),
),
),
),
);
},
),
);
}
}
class LoadingDialog extends StatelessWidget {
static void show(BuildContext context, {Key? key}) => showDialog<void>(
context: context,
useRootNavigator: false,
barrierDismissible: false,
builder: (_) => LoadingDialog(key: key),
).then((_) => FocusScope.of(context).requestFocus(FocusNode()));
static void hide(BuildContext context) => Navigator.pop(context);
const LoadingDialog({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return WillPopScope(
onWillPop: () async => false,
child: Center(
child: Card(
child: Container(
width: 80,
height: 80,
padding: const EdgeInsets.all(12.0),
child: const CircularProgressIndicator(),
),
),
),
);
}
}
class SuccessScreen extends StatelessWidget {
const SuccessScreen({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return Scaffold(
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
const Icon(Icons.tag_faces, size: 100),
const SizedBox(height: 10),
const Text(
'Success',
style: TextStyle(fontSize: 54, color: Colors.black),
textAlign: TextAlign.center,
),
const SizedBox(height: 10),
ElevatedButton.icon(
onPressed: () => Navigator.of(context).pushReplacement(
MaterialPageRoute(builder: (_) => const LoginForm())),
icon: const Icon(Icons.replay),
label: const Text('AGAIN'),
),
],
),
),
);
}
}
In my class LoginForm where I set appBar: AppBar(title: const Text('Basic Calculator - ')), I want to show the date and time of build/run in front of the hypen. I am not able to achieve it any way.
I have tried:
const Text('Basic Calculator - '+DateTime.now())
assigned the DateTime.now() to a variable and used the variable
but to no avail.

Answer 1

Remove const and add toString()
Text('Basic Calculator - '+ DateTime.now().toString())
This works during run-time.