polaris/ui/lib/calendar.dart

import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:table_calendar/table_calendar.dart';

class Calendar extends ConsumerStatefulWidget {
  @override
  ConsumerState<ConsumerStatefulWidget> createState() {
    return _CalendarSate();
  }
}

class _CalendarSate extends ConsumerState<Calendar> {
  DateTime? _selectedDay;
  DateTime _focusedDay = DateTime.now();
  CalendarFormat _calendarFormat = CalendarFormat.month;

  @override
  Widget build(BuildContext context) {
    return TableCalendar(
      locale: "zh_CN",
      firstDay: DateTime.utc(2010, 10, 16),
      lastDay: DateTime.utc(2030, 3, 14),
      focusedDay: _focusedDay,
      selectedDayPredicate: (day) {
        return isSameDay(_selectedDay, day);
      },
      onDaySelected: (selectedDay, focusedDay) {
        setState(() {
          _selectedDay = selectedDay;
          _focusedDay = focusedDay; // update `_focusedDay` here as well
        });
      },
      calendarFormat: _calendarFormat,
      onFormatChanged: (format) {
        setState(() {
          _calendarFormat = format;
        });
      },

      //locale: "zh_CN",
      //eventLoader: (day) {},
    );
  }
}

showCalendar(BuildContext context) {
  return showDialog<void>(
    context: context,
    barrierDismissible: true,
    builder: (BuildContext context) {
      return AlertDialog(
        //title: Text("资源"),
        content: SizedBox(
            width: MediaQuery.of(context).size.width * 0.7,
            height: MediaQuery.of(context).size.height * 0.6,
            child: Calendar()),
      );
    },
  );
}