Widget _buildSimple(BuildContext context) {
  final size = MediaQuery.of(context).size;
  final selected = ValueNotifier<List<int>>([DateTime.now().millisecondsSinceEpoch]);
  return ValueListenableBuilder(
    valueListenable: selected,
    builder: (context, value, child) {
      final date = DateTime.fromMillisecondsSinceEpoch(value[0]);
      return TDCellGroup(
        cells: [
          TDCell(
            title: '单个选择日历',
            arrow: true,
            note: '${date.year}-${date.month}-${date.day}',
            onClick: (cell) {
              TDCalendarPopup(
                context,
                visible: true,
                onConfirm: (value) {
                  print('onConfirm:$value');
                  selected.value = value;
                },
                onClose: () {
                  print('onClose');
                },
                child: TDCalendar(
                  title: '请选择日期',
                  value: value,
                  height: size.height * 0.6 + 176,
                  onCellClick: (value, type, tdate) {
                    print('onCellClick:$value');
                  },
                  onCellLongPress: (value, type, tdate) {
                    print('onCellLongPress:$value');
                  },
                  onHeanderClick: (index, week) {
                    print('onHeanderClick:$week');
                  },
                  onChange: (value) {
                    print('onChange:$value');
                  },
                ),
              );
            },
          ),
          TDCell(
            title: '多个选择日历',
            arrow: true,
            onClick: (cell) {
              TDCalendarPopup(
                context,
                visible: true,
                child: TDCalendar(
                  title: '请选择日期',
                  type: CalendarType.multiple,
                  value: [DateTime.now().millisecondsSinceEpoch],
                  height: size.height * 0.6 + 176,
                ),
              );
            },
          ),
          TDCell(
            title: '区间选择日历',
            arrow: true,
            onClick: (cell) {
              TDCalendarPopup(
                context,
                visible: true,
                child: TDCalendar(
                  title: '请选择日期区间',
                  type: CalendarType.range,
                  value: [
                    DateTime.now().millisecondsSinceEpoch,
                    DateTime.now().add(const Duration(days: 6)).millisecondsSinceEpoch,
                  ],
                  height: size.height * 0.6 + 176,
                ),
              );
            },
          ),
          TDCell(
            title: '单个选择日历和时间',
            arrow: true,
            note: '${date.year}-${date.month}-${date.day} ${date.hour}:${date.minute}',
            onClick: (cell) {
              TDCalendarPopup(
                context,
                visible: true,
                onConfirm: (value) {
                  print('onConfirm:$value');
                  selected.value = value;
                },
                onClose: () {
                  print('onClose');
                },
                child: TDCalendar(
                  title: '请选择日期和时间',
                  value: value,
                  height: size.height * 0.92,
                  useTimePicker: true,
                  onCellClick: (value, type, tdate) {
                    print('onCellClick:$value');
                  },
                  onCellLongPress: (value, type, tdate) {
                    print('onCellLongPress:$value');
                  },
                  onHeanderClick: (index, week) {
                    print('onHeanderClick:$week');
                  },
                  onChange: (value) {
                    print('onChange:$value');
                  },
                ),
              );
            },
          ),
          TDCell(
            title: '区间选择日历和时间',
            arrow: true,
            onClick: (cell) {
              TDCalendarPopup(
                context,
                visible: true,
                onConfirm: (value) {
                  print('onConfirm:$value');
                },
                onClose: () {
                  print('onClose');
                },
                child: TDCalendar(
                  title: '请选择日期和时间区间',
                  height: size.height * 0.92,
                  type: CalendarType.range,
                  value: [
                    DateTime.now().millisecondsSinceEpoch,
                    DateTime.now().add(const Duration(days: 3)).millisecondsSinceEpoch,
                  ],
                  useTimePicker: true,
                  onCellClick: (value, type, tdate) {
                    print('onCellClick:$value');
                  },
                  onCellLongPress: (value, type, tdate) {
                    print('onCellLongPress:$value');
                  },
                  onHeanderClick: (index, week) {
                    print('onHeanderClick:$week');
                  },
                  onChange: (value) {
                    print('onChange:$value');
                  },
                ),
              );
            },
          ),
        ],
      );
    },
  );
}