Calender Picker
final TextEditingController dateController = TextEditingController();
write this code inside onclick function
DateTime? pickedDate = await showDatePicker(
context: context,
initialDate: DateTime.now(), //get today's date
firstDate:DateTime(1800), //DateTime.now() - not to allow to choose before today.
lastDate: DateTime(2101)
);
if(pickedDate != null ){
print(pickedDate); //get the picked date in the format => 2022-07-04 00:00:00.000
String formattedDate = DateFormat('yyyy-MM-dd').format(pickedDate); // format date in required form here we use yyyy-MM-dd that means time is removed
print(formattedDate); //formatted date output using intl package => 2022-07-04
//You can format date as per your need
setState(() {
dateController.text = formattedDate.toString(); //set foratted date to TextField value.
});
}else{
print("Date is not selected");
}