flutter_custom_calendar/lib/widget/month_view.dart

import 'package:flutter/material.dart';
import 'package:flutter_custom_calendar/CalendarProvider.dart';
import 'package:flutter_custom_calendar/configuration.dart';
import 'package:flutter_custom_calendar/constants/constants.dart';
import 'package:flutter_custom_calendar/model/date_model.dart';
import 'package:flutter_custom_calendar/utils/date_util.dart';
import 'package:provider/provider.dart';

/**
 * 月视图，显示整个月的日子
 */
class MonthView extends StatefulWidget {
//  OnCalendarSelect onCalendarSelectListener;

//  Set<DateModel> selectedDateList; //被选中的日期
//
//  DateModel selectDateModel; //当前选择项,用于单选
//
//  DayWidgetBuilder dayWidgetBuilder;
//
//  OnMultiSelectOutOfRange multiSelectOutOfRange; //多选超出指定范围
//  OnMultiSelectOutOfSize multiSelectOutOfSize; //多选超出限制个数

  int year;
  int month;
  int day;

  DateModel minSelectDate;
  DateModel maxSelectDate;

  Map<DateTime, Object> extraDataMap; //自定义额外的数据

  MonthView({
    @required this.year,
    @required this.month,
    this.day,
    this.minSelectDate,
    this.maxSelectDate,
  });

  @override
  _MonthViewState createState() => _MonthViewState();
}

class _MonthViewState extends State<MonthView> {
  List<DateModel> items;

  int lineCount;

  double itemHeight;
  double totalHeight;
  double mainSpacing = 10;

  @override
  void initState() {
    super.initState();

    items = DateUtil.initCalendarForMonthView(
        widget.year, widget.month, DateTime.now(), DateTime.sunday,
        minSelectDate: widget.minSelectDate,
        maxSelectDate: widget.maxSelectDate,
        extraDataMap: widget.extraDataMap);

    lineCount = DateUtil.getMonthViewLineCount(widget.year, widget.month);
  }

  @override
  Widget build(BuildContext context) {
    itemHeight = MediaQuery.of(context).size.width / 7;
    totalHeight = itemHeight * lineCount + mainSpacing * (lineCount - 1);

    return GestureDetector(
        onVerticalDragStart: (DragStartDetails detail) {
          print("onHorizontalDragStart:$detail");
        },
        child: Container(height: totalHeight, child: getView()));
  }

  Widget getView() {
    return Consumer<CalendarProvider>(
        builder: (context, calendarProvider, child) {
      CalendarConfiguration configuration =
          calendarProvider.calendarConfiguration;
      print(
          "Consumer:calendarProvider.selectDateModel:${calendarProvider.selectDateModel}");
      return new GridView.builder(
          physics: NeverScrollableScrollPhysics(),
          gridDelegate: new SliverGridDelegateWithFixedCrossAxisCount(
              crossAxisCount: 7, mainAxisSpacing: 10),
          itemCount: 7 * lineCount,
          itemBuilder: (context, index) {
            DateModel dateModel = items[index];
            //判断是否被选择
            if (configuration.selectMode == Constants.MODE_MULTI_SELECT) {
              if (calendarProvider.selectedDateList.contains(dateModel)) {
                dateModel.isSelected = true;
              } else {
                dateModel.isSelected = false;
              }
            } else {
              if (calendarProvider.selectDateModel == dateModel) {
                dateModel.isSelected = true;
              } else {
                dateModel.isSelected = false;
              }
            }

            return GestureDetector(
              onTap: () {
                print("GestureDetector onTap：$dateModel");
                //范围外不可点击
                if (!dateModel.isInRange) {
                  //多选回调
                  if (configuration.selectMode == Constants.MODE_MULTI_SELECT) {
                    configuration.multiSelectOutOfRange();
                  }
                  return;
                }

                if (configuration.selectMode == Constants.MODE_MULTI_SELECT) {
                  //多选，判断是否超过限制，超过范围
                  if (calendarProvider.selectedDateList.length ==
                      configuration.maxMultiSelectCount) {
                    configuration.multiSelectOutOfSize();
                    return;
                  }

                  //多选也可以弄这些单选的代码
                  calendarProvider.selectDateModel = dateModel;
                  configuration.calendarSelect(dateModel);
                  setState(() {
                    if (calendarProvider.selectedDateList.contains(dateModel)) {
                      calendarProvider.selectedDateList.remove(dateModel);
                    } else {
                      calendarProvider.selectedDateList.add(dateModel);
                    }
                  });
                } else {
                  calendarProvider.selectDateModel = dateModel;
                  configuration.calendarSelect(dateModel);
                }
              },
              child: configuration.dayWidgetBuilder(dateModel),
            );
          });
    });
  }
}