Flutter 如何使用Firestore数据库快照填充表日历

我正在尝试填充要显示在TableCalendar上的事件地图（使用table calendar软件包）

要填写这些活动，我需要一张地图

因此，在开始时，我创建了以下内容：

Map<DateTime, List<Event>> _events;

从现在起，日历就可以正常工作了。 问题是当我尝试从firestore快照添加数据时。我完全不知道如何将数据从快照添加到事件映射。你会看到我将添加一条评论，如。。我在这里迷路了

Widget build(BuildContext context) {
    return Scaffold(
      appBar: popAppBar(context, 'Horaire'),
      body: StreamBuilder(
          stream: Firestore.instance
              .collection('nurseries')
              .document(widget._favoriteNurseryId)
              .collection('events')
              .snapshots(),
          builder: (context, eventsSnapshot) {
            if (eventsSnapshot.connectionState == ConnectionState.waiting) {
              return CircularProgressIndicator();
            }
            if (eventsSnapshot.hasError) {
              return Center(
                  child: Text('Il y a une erreur dans votre calendrier'));
            }
            for (var i = 0; i < eventsSnapshot.data.lenght; i++) {
              _events.addEntries( //IM LOST HERE// );
            }
            
            return TableCalendar(
              locale: 'fr_FR',
              holidays: _holidays,
              events: _events,
              calendarController: _calendarController,
              initialCalendarFormat: CalendarFormat.month,

小部件构建（构建上下文）{
返回脚手架(
appBar:popAppBar（上下文“Horaire”），
正文：StreamBuilder(
流：Firestore.instance
.收藏（“托儿所”）
.document（widget.\u favoriteNurseryId）
.collection（“事件”）
.snapshots（），
生成器：（上下文，事件快照）{
if（eventsSnapshot.connectionState==connectionState.waiting）{
返回循环ProgressIndicator（）；
}
if（eventsSnapshot.hasError）{
返回中心(
子项：文本（'Il y a une erreur dans votre calendrier'）；
}
对于（var i=0；i

以下是我在项目中是如何做到这一点的

if(snapshot.hasData){
      //parse json array here and input the list of events for the months
      List<CalendarItemData> snapData = snapshot.data;
      calendarList = snapData;
      _events = convertToMap(snapData);
      print(_events.toString());
      _selectedEvents = _events[_selectedDay] ?? [];
      return buildBody();
    }else if(snapshot.hasError){
      return Padding(
        padding: const EdgeInsets.all(10),
        child:Text(
          'There are no events in the Calendar for the selected category.',
          style:TextStyle(
              fontFamily:'Raleway',
              fontWeight:FontWeight.bold,
              fontSize:18),
          textAlign:TextAlign.center,
        ),
      );
}

//method to change calendar item to Map<DateTime,List>
Map<DateTime,List> convertToMap(List<CalendarItemData> item){
Map<DateTime, List> result;

for(int i = 0; i < item.length; i++){
  CalendarItemData data = item[i];
  //get the date and convert it to a DateTime variable
  DateTime currentDate = dateFormat.parse(data.eventDate);
  List eventNames = [];
  //add the event name to the the eventNames list for the current date.
  //search for another event with the same date and populate the eventNames List.
  for(int j = 0; j < item.length; j++){
    //create temp calendarItemData object.
    CalendarItemData temp = item[j];
    //establish that the temp date is equal to the current date
    if(data.eventDate == temp.eventDate) {
      //add the event name to the event List.
      eventNames.add(temp.eventName);
    } //else continue
  }

  //add the date and the event to the map if the date is not contained in the map
  if(result == null){
    result = {
      currentDate: eventNames
    };
  }else {
    result[currentDate] = eventNames;
  }
}

print(result);
return result;
}

if（snapshot.hasData）{
//在这里解析json数组并输入月份的事件列表
List snapData=snapshot.data；
calendarList=snapData；
_事件=转换映射（snapData）；
打印（_events.toString（））；
_selectedEvents=_事件[_selectedDay]？？[]；
返回buildBody（）；
}else if（snapshot.hasrerror）{
返回填充(
填充：常量边集。全部（10），
子：文本(
“日历中没有所选类别的事件。”，
样式：TextStyle(
fontFamily:‘Raleway’，
fontWeight:fontWeight.bold，
尺寸:18),，
textAlign:textAlign.center，
),
);
}
//方法将日历项更改为映射
映射转换映射（列表项）{
地图结果；
对于（int i=0；i

---

希望这有助于解决您的问题。

谢谢，我将在今晚或明天继续我的项目时尝试。CalendarItemData在哪里定义？

if(snapshot.hasData){
      //parse json array here and input the list of events for the months
      List<CalendarItemData> snapData = snapshot.data;
      calendarList = snapData;
      _events = convertToMap(snapData);
      print(_events.toString());
      _selectedEvents = _events[_selectedDay] ?? [];
      return buildBody();
    }else if(snapshot.hasError){
      return Padding(
        padding: const EdgeInsets.all(10),
        child:Text(
          'There are no events in the Calendar for the selected category.',
          style:TextStyle(
              fontFamily:'Raleway',
              fontWeight:FontWeight.bold,
              fontSize:18),
          textAlign:TextAlign.center,
        ),
      );
}

//method to change calendar item to Map<DateTime,List>
Map<DateTime,List> convertToMap(List<CalendarItemData> item){
Map<DateTime, List> result;

for(int i = 0; i < item.length; i++){
  CalendarItemData data = item[i];
  //get the date and convert it to a DateTime variable
  DateTime currentDate = dateFormat.parse(data.eventDate);
  List eventNames = [];
  //add the event name to the the eventNames list for the current date.
  //search for another event with the same date and populate the eventNames List.
  for(int j = 0; j < item.length; j++){
    //create temp calendarItemData object.
    CalendarItemData temp = item[j];
    //establish that the temp date is equal to the current date
    if(data.eventDate == temp.eventDate) {
      //add the event name to the event List.
      eventNames.add(temp.eventName);
    } //else continue
  }

  //add the date and the event to the map if the date is not contained in the map
  if(result == null){
    result = {
      currentDate: eventNames
    };
  }else {
    result[currentDate] = eventNames;
  }
}

print(result);
return result;
}