Flutter, DateTime.now() is not working in my code - flutter

Question

I've been developing an application for both iOS and Android.
The code below makes real-time screen which shows current time.
1.I confirmed that DateTime.now() is working on both OS.
2.Also i confirmed that it is working at the actual Android device and Android emulator.
But everytime when i am trying to test on iOS(both emulator and actual device), _timeString always get a null.
What is wrong with this code? I don't get it.
Here is my environment in advance for solving my question.
VMware workstation 15 Player, Xcode 10.3, Android Studio 3.4.2
import 'package:flutter/material.dart';
import 'dart:async';
import 'package:intl/intl.dart';
class TableLayout extends StatefulWidget {
#override
_TableLayoutState createState() => _TableLayoutState();
}
class _TableLayoutState extends State<TableLayout> {
String _timeString;
String _formatDateTime(DateTime dateTime) {
return DateFormat('MM/dd/yyyy HH:mm:ss').format(dateTime);
}
#override
void initState() {
_timeString = _formatDateTime(DateTime.now());
Timer.periodic(Duration(milliseconds: 1000), (Timer t) => _getTime());
super.initState();
}
void _getTime() {
DateTime _now = DateTime.now();
final String formattedDateTime = _formatDateTime(_now);
if (this.mounted) {
setState(() {
_timeString = formattedDateTime;
});
}
}
#override
Widget build(BuildContext context) {
return
Scaffold(
body:
Container(
child:
Text("\n\n\n\n${_timeString}")
)
);
}
}

Answer 1

Try this by changing date format
To
MM/dd/yyyy hh:mm:ss

Answer 2

I ran your code without any change. (Added a entry point however)
and it works as expected.
Any additional information regarding the intl package will be helpful. Here is my entire app and the result of that below.
My dependency is intl: ^0.15.8.
import 'package:flutter/material.dart';
import 'dart:async';
import 'package:intl/intl.dart';
void main()
{
runApp(SampleApp());
}
class SampleApp extends StatelessWidget {
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Sample App',
home: TableLayout(),
);
}
}
class TableLayout extends StatefulWidget {
#override
_TableLayoutState createState() => _TableLayoutState();
}
class _TableLayoutState extends State<TableLayout> {
String _timeString;
String _formatDateTime(DateTime dateTime) {
return DateFormat('MM/dd/yyyy HH:mm:ss').format(dateTime);
}
#override
void initState() {
_timeString = _formatDateTime(DateTime.now());
Timer.periodic(Duration(milliseconds: 1000), (Timer t) => _getTime());
super.initState();
}
void _getTime() {
DateTime _now = DateTime.now();
final String formattedDateTime = _formatDateTime(_now);
if (this.mounted) {
setState(() {
_timeString = formattedDateTime;
});
}
}
#override
Widget build(BuildContext context) {
return
Scaffold(
body:
Container(
child:
Text("\n\n\n\n${_timeString}")
)
);
}
}
App running on IOS simulator