onDatePickerModeChange property
final
Called when the DatePickerDialog is toggled between DatePickerEntryMode.calendar,DatePickerEntryMode.input.
An example of how this callback might be used is an app that saves the
user's preferred entry mode and uses it to initialize the
initialEntryMode parameter the next time the date picker is shown.
Implementation
final ValueChanged<DatePickerEntryMode>? onDatePickerModeChange;