多选模式bug修复：超过指定个数后，报错空指针

多选模式无效的问题

example/lib/multi_select_style_page.dart

@@ -28,6 +28,9 @@ class _MultiSelectStylePageState extends State<MultiSelectStylePage> {
       minSelectYear: 2019,
       minSelectMonth: 5,
       minSelectDay: 20,
+      selectedDateTimeList: {
+        DateTime.now(),
+      }
     );
 
     controller.addMonthChangeListener(
@@ -45,7 +48,7 @@ class _MultiSelectStylePageState extends State<MultiSelectStylePage> {
     text = new ValueNotifier("${DateTime.now().year}年${DateTime.now().month}月");
 
     selectText = new ValueNotifier(
-        "多选模式\n选中的时间:\n${controller.getSingleSelectCalendar()}");
+        "多选模式\n选中的时间:\n${controller.getMultiSelectCalendar().join("\n")}");
   }
 
   @override

lib/calendar_provider.dart

@@ -1,3 +1,5 @@
+import 'dart:collection';
+
 import 'package:flutter/material.dart';
 import 'package:flutter_custom_calendar/cache_data.dart';
 import 'package:flutter_custom_calendar/configuration.dart';
@@ -15,7 +17,7 @@ import 'package:flutter_custom_calendar/widget/month_view.dart';
  */
 class CalendarProvider extends ChangeNotifier {
   double _totalHeight; //当前月视图的整体高度
-  Set<DateModel> selectedDateList = new Set(); //被选中的日期,用于多选
+  HashSet<DateModel> selectedDateList = new HashSet<DateModel>(); //被选中的日期,用于多选
   DateModel _selectDateModel; //当前选中的日期，用于单选
   ItemContainerState lastClickItemState;
   DateModel _lastClickDateModel;
@@ -117,17 +119,20 @@ class CalendarProvider extends ChangeNotifier {
     WeekBarItemWidgetBuilder weekBarItemWidgetBuilder,
   }) {
     LogUtil.log(TAG: this.runtimeType, message: "CalendarProvider initData");
-    if (selectedDateList != null) {
-      this.selectedDateList.addAll(selectedDateList);
-    }
-    this.selectDateModel = selectDateModel;
     this.calendarConfiguration = calendarConfiguration;
+    print(
+        "calendarConfiguration.defaultSelectedDateList:${calendarConfiguration.defaultSelectedDateList}");
+    this
+        .selectedDateList
+        .addAll(this.calendarConfiguration.defaultSelectedDateList);
+    this.selectDateModel = this.calendarConfiguration.selectDateModel;
     this.calendarConfiguration.padding = padding;
     this.calendarConfiguration.margin = margin;
     this.calendarConfiguration.itemSize = itemSize;
     this.calendarConfiguration.verticalSpacing = verticalSpacing;
     this.calendarConfiguration.dayWidgetBuilder = dayWidgetBuilder;
-    this.calendarConfiguration.weekBarItemWidgetBuilder=weekBarItemWidgetBuilder;
+    this.calendarConfiguration.weekBarItemWidgetBuilder =
+        weekBarItemWidgetBuilder;
 
     //lastClickDateModel，默认是选中的item，如果为空的话，默认是当前的时间
     this.lastClickDateModel = selectDateModel != null
@@ -149,8 +154,8 @@ class CalendarProvider extends ChangeNotifier {
           MediaQueryData.fromWindow(WidgetsBinding.instance.window);
       if (mediaQueryData.orientation == Orientation.landscape) {
         calendarConfiguration.itemSize = (mediaQueryData.size.height -
-                calendarConfiguration.padding.horizontal -
+                calendarConfiguration.padding.vertical -
-                calendarConfiguration.margin.horizontal) /
+                calendarConfiguration.margin.vertical) /
             7;
       } else {
         calendarConfiguration.itemSize = (mediaQueryData.size.width -
@@ -171,8 +176,6 @@ class CalendarProvider extends ChangeNotifier {
           calendarConfiguration.nowYear, calendarConfiguration.nowMonth);
       totalHeight = calendarConfiguration.itemSize * (lineCount) +
           calendarConfiguration.verticalSpacing * (lineCount - 1);
-      print(
-          "1111111:totalHeight:$totalHeight,lineCount:$lineCount,calendarConfiguration.nowYear:${calendarConfiguration.nowYear},calendarConfiguration.nowMonth:${calendarConfiguration.nowMonth}");
     } else {
       totalHeight = calendarConfiguration.itemSize;
     }

lib/configuration.dart

@@ -1,3 +1,5 @@
+import 'dart:collection';
+
 import 'package:flutter/material.dart';
 import 'package:flutter_custom_calendar/controller.dart';
 import 'package:flutter_custom_calendar/model/date_model.dart';
@@ -34,7 +36,8 @@ class CalendarConfiguration {
   int maxSelectMonth;
   int maxSelectDay; //注意：不能超过对应月份的总天数
 
-  Set<DateModel> defaultSelectedDateList = new Set(); //默认被选中的日期
+  DateModel selectDateModel; //默认被选中的item，用于单选
+  HashSet<DateModel> defaultSelectedDateList; //默认被选中的日期set，用于多选
   int maxMultiSelectCount; //多选，最多选多少个
   Map<DateModel, Object> extraDataMap = new Map(); //自定义额外的数据
 
@@ -70,6 +73,8 @@ class CalendarConfiguration {
   List<DateModel> weekList = new List(); //星期list
   PageController monthController; //月份的controller
   PageController weekController; //星期的controller
+  DateModel minSelectDate;
+  DateModel maxSelectDate;
 
   CalendarConfiguration(
       {this.selectMode,
@@ -86,6 +91,7 @@ class CalendarConfiguration {
       this.maxSelectMonth,
       this.maxSelectDay,
       this.defaultSelectedDateList,
+      this.selectDateModel,
       this.maxMultiSelectCount,
       this.extraDataMap,
       this.monthList,

lib/controller.dart

@@ -1,3 +1,5 @@
+import 'dart:collection';
+
 import 'package:flutter/material.dart';
 import 'package:flutter_custom_calendar/calendar_provider.dart';
 import 'package:flutter_custom_calendar/configuration.dart';
@@ -45,8 +47,8 @@ class CalendarController {
       int maxSelectYear = 2055,
       int maxSelectMonth = 12,
       int maxSelectDay = 30,
-      Set<DateTime> selectedDateTimeList = EMPTY_SET,
+      Set<DateTime> selectedDateTimeList = EMPTY_SET, //多选模式下，默认选中的item列表
-      DateModel selectDateModel,
+      DateModel selectDateModel, //单选模式下，默认选中的item
       int maxMultiSelectCount = 9999,
       Map<DateModel, Object> extraDataMap = EMPTY_MAP}) {
     LogUtil.log(TAG: this.runtimeType, message: "init CalendarConfiguration");
@@ -73,14 +75,26 @@ class CalendarController {
         maxSelectMonth: maxSelectMonth,
         extraDataMap: extraDataMap,
         maxSelectDay: maxSelectDay,
-    );
+        maxMultiSelectCount: maxMultiSelectCount,
+        selectDateModel: selectDateModel);
 
-    if (selectedDateTimeList != null && selectedDateTimeList.isNotEmpty) {
+    calendarConfiguration.defaultSelectedDateList = new HashSet<DateModel>();
     calendarConfiguration.defaultSelectedDateList
         .addAll(selectedDateTimeList.map((dateTime) {
       return DateModel.fromDateTime(dateTime);
     }).toSet());
-    }
+    //将默认选中的数据，放到provider中
+    calendarProvider.selectDateModel = selectDateModel;
+    calendarProvider.selectedDateList =
+        calendarConfiguration.defaultSelectedDateList;
+    calendarConfiguration.minSelectDate = DateModel.fromDateTime(DateTime(
+        calendarConfiguration.minSelectYear,
+        calendarConfiguration.minSelectMonth,
+        calendarConfiguration.minSelectDay));
+    calendarConfiguration.maxSelectDate = DateModel.fromDateTime(DateTime(
+        calendarConfiguration.maxSelectYear,
+        calendarConfiguration.maxSelectMonth,
+        calendarConfiguration.maxSelectDay));
 
     LogUtil.log(
         TAG: this.runtimeType,
@@ -109,11 +123,6 @@ class CalendarController {
           dateModel.year = i;
           dateModel.month = j;
 
-          //如果没有配置当前时间，设置成当前的时间
-          if (nowYear == -1 || nowMonth == -1) {
-            nowYear = DateTime.now().year;
-            nowMonth = DateTime.now().month;
-          }
           if (i == nowYear && j == nowMonth) {
             initialPage = nowMonthIndex;
           }
@@ -127,14 +136,13 @@ class CalendarController {
       LogUtil.log(
           TAG: this.runtimeType,
           message:
-              "初始化月份视图的信息:一共有${monthList.length}个月，initialPage为${nowMonthIndex}");
+              "初始化月份视图的信息:一共有${monthList.length}个月，initialPage为$nowMonthIndex");
     }
 
     if (showMode != CalendarConstants.MODE_SHOW_ONLY_MONTH) {
       //计算一共多少周
       //计算方法：第一天是周几，最后一天是周几，中间的天数/7后加上2就是结果了
       int initialWeekPage = 0;
-      int nowWeekIndex = 0;
       weekList.clear();
       //如果没有配置当前时间，设置成当前的时间
       if (nowYear == -1 || nowMonth == -1) {
@@ -166,7 +174,7 @@ class CalendarController {
       LogUtil.log(
           TAG: this.runtimeType,
           message:
-              "初始化星期视图的信息:一共有${weekList.length}个星期，initialPage为${initialWeekPage}");
+              "初始化星期视图的信息:一共有${weekList.length}个星期，initialPage为$initialWeekPage");
       this.weekController = new PageController(initialPage: initialWeekPage);
     }
 
@@ -218,6 +226,19 @@ class CalendarController {
     this.calendarProvider.generation.value++;
   }
 
+  //可以动态修改默认选中的item。
+  void changeDefaultSelectedDateList(Set<DateModel> defaultSelectedDateList) {
+    this.calendarConfiguration.defaultSelectedDateList =
+        defaultSelectedDateList;
+    this.calendarProvider.generation.value++;
+  }
+
+  //可以动态修改默认选中的item
+  void changeDefaultSelectedDateModel(DateModel dateModel) {
+    this.calendarProvider.selectDateModel = dateModel;
+    this.calendarProvider.generation.value++;
+  }
+
   /**
    * 月份或者星期的上一页
    */

lib/widget/calendar_view.dart

@@ -28,6 +28,7 @@ class CalendarViewWidget extends StatefulWidget {
   //日历item之间的竖直方向间距，默认10
   final double verticalSpacing;
 
+  //自定义日历item
   final DayWidgetBuilder dayWidgetBuilder;
   final WeekBarItemWidgetBuilder weekBarItemWidgetBuilder;
 

lib/widget/month_view.dart

@@ -36,27 +36,11 @@ class _MonthViewState extends State<MonthView>
   List<DateModel> items = List();
 
   int lineCount;
-
-//  double itemHeight;
-//  double totalHeight;
-//  double mainSpacing = 10;
-
-  DateModel minSelectDate;
-  DateModel maxSelectDate;
   Map<DateModel, Object> extraDataMap; //自定义额外的数据
 
   @override
   void initState() {
     super.initState();
-
-    minSelectDate = DateModel.fromDateTime(DateTime(
-        widget.configuration.minSelectYear,
-        widget.configuration.minSelectMonth,
-        widget.configuration.minSelectDay));
-    maxSelectDate = DateModel.fromDateTime(DateTime(
-        widget.configuration.maxSelectYear,
-        widget.configuration.maxSelectMonth,
-        widget.configuration.maxSelectDay));
     extraDataMap = widget.configuration.extraDataMap;
 
     DateModel firstDayOfMonth =
@@ -73,12 +57,12 @@ class _MonthViewState extends State<MonthView>
 
     lineCount = DateUtil.getMonthViewLineCount(widget.year, widget.month);
 
-    //第一帧后
+    //第一帧后,添加监听，generation发生变化后，需要刷新整个日历
     WidgetsBinding.instance.addPostFrameCallback((callback) {
       Provider.of<CalendarProvider>(context, listen: false)
           .generation
           .addListener(() async {
-        extraDataMap={};
+        extraDataMap = widget.configuration.extraDataMap;
         await getItems();
       });
     });
@@ -88,8 +72,8 @@ class _MonthViewState extends State<MonthView>
     items = await compute(initCalendarForMonthView, {
       'year': widget.year,
       'month': widget.month,
-      'minSelectDate': minSelectDate,
+      'minSelectDate': widget.configuration.minSelectDate,
-      'maxSelectDate': maxSelectDate,
+      'maxSelectDate': widget.configuration.maxSelectDate,
       'extraDataMap': extraDataMap
     });
     setState(() {});
@@ -139,7 +123,8 @@ class _MonthViewState extends State<MonthView>
 
           return ItemContainer(
             dateModel: dateModel,
-            key: ObjectKey(dateModel),//这里使用objectKey，保证可以刷新。原因1：跟flutter的刷新机制有关。原因2：statefulElement持有state。
+            key: ObjectKey(
+                dateModel), //这里使用objectKey，保证可以刷新。原因1：跟flutter的刷新机制有关。原因2：statefulElement持有state。
           );
         });
   }
@@ -175,6 +160,13 @@ class ItemContainerState extends State<ItemContainer> {
     super.initState();
     dateModel = widget.dateModel;
     isSelected = ValueNotifier(dateModel.isSelected);
+
+    WidgetsBinding.instance.addPostFrameCallback((callback) {
+      if (configuration.selectMode == CalendarConstants.MODE_SINGLE_SELECT &&
+          dateModel.isSelected) {
+        calendarProvider.lastClickItemState = this;
+      }
+    });
   }
 
   /**
@@ -220,16 +212,17 @@ class ItemContainerState extends State<ItemContainer> {
         calendarProvider.lastClickDateModel = dateModel;
 
         if (configuration.selectMode == CalendarConstants.MODE_MULTI_SELECT) {
+          if (calendarProvider.selectedDateList.contains(dateModel)) {
+            calendarProvider.selectedDateList.remove(dateModel);
+          } else {
             //多选，判断是否超过限制，超过范围
             if (calendarProvider.selectedDateList.length ==
                 configuration.maxMultiSelectCount) {
+              if (configuration.multiSelectOutOfSize != null) {
                 configuration.multiSelectOutOfSize();
+              }
               return;
             }
-
-          if (calendarProvider.selectedDateList.contains(dateModel)) {
-            calendarProvider.selectedDateList.remove(dateModel);
-          } else {
             calendarProvider.selectedDateList.add(dateModel);
           }
           configuration.calendarSelect(dateModel);
@@ -241,9 +234,11 @@ class ItemContainerState extends State<ItemContainer> {
           configuration.calendarSelect(dateModel);
 
           //单选需要刷新上一个item
+          if (calendarProvider.lastClickItemState != this) {
             calendarProvider.lastClickItemState?.refreshItem();
             calendarProvider.lastClickItemState = this;
           }
+        }
 
         refreshItem();
       },

lib/widget/week_view.dart

@@ -29,29 +29,32 @@ class WeekView extends StatefulWidget {
 class _WeekViewState extends State<WeekView> {
   List<DateModel> items;
 
-  DateModel minSelectDate;
-  DateModel maxSelectDate;
-
   Map<DateModel, Object> extraDataMap; //自定义额外的数据
 
   @override
   void initState() {
     super.initState();
-    minSelectDate = DateModel.fromDateTime(DateTime(
-        widget.configuration.minSelectYear,
-        widget.configuration.minSelectMonth,
-        widget.configuration.minSelectDay));
-    maxSelectDate = DateModel.fromDateTime(DateTime(
-        widget.configuration.maxSelectYear,
-        widget.configuration.maxSelectMonth,
-        widget.configuration.maxSelectDay));
     extraDataMap = widget.configuration.extraDataMap;
 
     items = DateUtil.initCalendarForWeekView(
         widget.year, widget.month, widget.firstDayOfWeek.getDateTime(), 0,
-        minSelectDate: minSelectDate,
+        minSelectDate: widget.configuration.minSelectDate,
-        maxSelectDate: maxSelectDate,
+        maxSelectDate: widget.configuration.maxSelectDate,
         extraDataMap: extraDataMap);
+
+    //第一帧后,添加监听，generation发生变化后，需要刷新整个日历
+    WidgetsBinding.instance.addPostFrameCallback((callback) {
+      Provider.of<CalendarProvider>(context, listen: false)
+          .generation
+          .addListener(() async {
+        items = DateUtil.initCalendarForWeekView(
+            widget.year, widget.month, widget.firstDayOfWeek.getDateTime(), 0,
+            minSelectDate: widget.configuration.minSelectDate,
+            maxSelectDate: widget.configuration.maxSelectDate,
+            extraDataMap: extraDataMap);
+        setState(() {});
+      });
+    });
   }
 
   @override