switchToCalendarEntryModeIcon property
An optional switchToCalendarEntryModeIcon argument can be used to
display a custom Icon in the corner of the dialog
when DatePickerEntryMode is DatePickerEntryMode.input. Clicking on
icon changes the DatePickerEntryMode to DatePickerEntryMode.calendar.
If null, Icon(Icons.calendar_today) is used.
Implementation
final Icon? switchToCalendarEntryModeIcon;