Date Picker is not showing when clicking the field - flutter - flutter

Question

Im building a registration screen that contains a form of input fields, one of the fields is to input the date of birth from user by showing the Date Picker when the user clicks the field, first i have created an instance of DateFormField and implemented the solution as follows:
//Date picker for birth of date field
final format = DateFormat('dd-mm-yyyy');
final birthDateField = DateTimeField(
decoration: InputDecoration(
border: OutlineInputBorder(
borderRadius: BorderRadius.circular(10),
),
labelText: 'تاريخ الميلاد',
prefixIcon: Icon(Icons.calendar_month),
),
format: format,
onShowPicker: (context, currentValue) async {
final date = showDatePicker(
context: context,
initialDate: currentValue ?? DateTime.now(),
firstDate: DateTime(1920),
lastDate: DateTime(2022));
return date;
},
);
Then i have rendered the birthDateField inside the Scaffold as follows:
return Scaffold(
backgroundColor: Colors.white,
body: Center(
//Use the SingleChildScrollView as a wrapper to ensure scrolling in case scrolling is needed.
child: SingleChildScrollView(
//wrap the elements with Container to provide flexibility in designing the elements.
child: Container(
color: Colors.white,
//use the form as a container of the input fields as it is a Registration form.
child: Padding(
padding: const EdgeInsets.all(36.0),
child: Form(
//give the form wrapper the key value to tell flutter that this is the form design for your form functions.
key: _formKey,
//use the column to show the elements in vertical array.
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
//Use children property inside the column to specify list of widgets
children: <Widget>[
nameField,
SizedBox(
height: 20,
),
emailField,
SizedBox(
height: 20,
),
passwordField,
SizedBox(
height: 20,
),
confirmPasswordField,
SizedBox(
height: 20,
),
birthDateField,
SizedBox(
height: 20,
),
]),
),
),
),
),
),
);
so after running the code the field appears normally but when clicking its not opening the picker, i tried to set a TextEdittingController i though its updating the state issue but doesn't work and its not showing any errors, i would be thankful if anyone have a idea of whats i am missing.
Note: i have imported the necessary libraries :
import 'dart:io';
import 'package:image_picker/image_picker.dart';
import 'package:intl/intl.dart';
import 'package:datetime_picker_formfield/datetime_picker_formfield.dart';
import 'package:flutter/material.dart';

Answer 1

The issue is here, last date is getting 2022/01/01 and current date is greater than last date.
In order to fix the issue, you need to provide last date which must be greater initial date. You can include lastDate: DateTime(2023)
onShowPicker: (context, currentValue) async {
final date = await showDatePicker(
context: context,
initialDate: currentValue ?? DateTime.now(),
firstDate: DateTime(1920),
lastDate: DateTime(2023));
return date;
},