我正在尝试从我的 firebase 实时数据库中获取一些数据。这是我的代码，以便通过 http 请求获取数据。我也收到了数据，并且可以在日志中看到它。
return http.get(placeUrl).then((value) {
var _extractedData = jsonDecode(value.body) as Map<String, dynamic>;
print("Data: $_extractedData");
_extractedData.forEach((_placeName, _details) {
print("Details: $_details");
var _events = _details['events'] as Map<String, dynamic>;
List<EventModel> events = [];
_events != null
? _events.forEach((_event, _eventDetail) {
print("_eventdetail: $_eventDetail");
List<PriceModel> prices = [];
var _price = _eventDetail['price'] as Map<String, dynamic>;
_price != null
? _price.forEach((_type, _typeDetail) {
print("_typeDetail: $_typeDetail");
List<TypeModel> typeModelList = [];
_typeDetail != null
? _typeDetail.forEach((_typeName, _typeSubDetail) {
print("_typeSubDetail: $_typeSubDetail");
var typeModel = TypeModel(
typeName: _typeName.toString(),
description:
_typeSubDetail['description'].toString(),
price: _typeSubDetail['price'].toString(),
);
typeModelList.add(typeModel);
})
: null;
var priceModel = PriceModel(
type: _type,
typeData: typeModelList,
);
prices.add(priceModel);
})
: null;
var _eventModel = EventModel(
ageLimit: _eventDetail['agelimit'].toString(),
date: _eventDetail['date'].toString(),
description: _eventDetail['description'].toString(),
dressCode: _eventDetail['dresscode'].toString(),
eventName: _event,
image: _eventDetail['image'].toString(),
lineup: _eventDetail['lineup'] as List<dynamic>,
prices: prices,
stars: double.parse(_eventDetail['stars']),
time: _eventDetail['time'].toString(),
);
events.add(_eventModel);
})
: null;
var _placeModel = PlaceModel(
description: _details['description'],
event: events,
images: _details['images'],
location: _details['location'],
menu: _details['menu'],
placeName: _placeName,
stars: double.parse("${_details['stars']}"),
logo: _details['logo'],
);
_places.add(_placeModel);
});
}).then((_) {
print("This is final: ${places[0].images[0]}");
notifyListeners();
}).catchError((e) {
print(e);
});
我得到的日志是：
I/flutter (25748): Data: {Amethhyyst - Mumbai: {description: In the city that never sleeps, rises a luxury lifestyle lounge built with one sole vision - Live life. One experience at a time!, events: {Saturday club night: {agelimit: 18+, date: Sat 7, Nov 2020, description: It's Club Night and the place will be exploding with amazing music and your tapping on the floor. The party starts at 7 PM, so be there on 07th Nov and rejoice with Dj Manzee @amethhyyst!, dresscode: casuals, image: https://firebasestorage.googleapis.com/v0/b/guestinme-3aafb.appspot.com/o/places%2Famethhyyst%2Fevent%2F07112020_flyer.jpg?alt=media&token=967c8301-7730-40fb-98e4-1dfe07e7e5aa, lineup: [DJ Manzee], price: {crowd: {Couple: {description: 1 male and 1 female only, price: 0}, Female: {description: 1 female only, price: 0}, Male Stags: {description: 1 male only, price: 2000}}, tables: {Exclusive Table: {description: Exclusive table provided, price: 10000}, VIP Table: {decription: VIP table provided, price: 20000}}}, time: 19:00 - 01:30}}, images: [http
I/flutter (25748): Details: {description: In the city that never sleeps, rises a luxury lifestyle lounge built with one sole vision - Live life. One experience at a time!, events: {Saturday club night: {agelimit: 18+, date: Sat 7, Nov 2020, description: It's Club Night and the place will be exploding with amazing music and your tapping on the floor. The party starts at 7 PM, so be there on 07th Nov and rejoice with Dj Manzee @amethhyyst!, dresscode: casuals, image: https://firebasestorage.googleapis.com/v0/b/guestinme-3aafb.appspot.com/o/places%2Famethhyyst%2Fevent%2F07112020_flyer.jpg?alt=media&token=967c8301-7730-40fb-98e4-1dfe07e7e5aa, lineup: [DJ Manzee], price: {crowd: {Couple: {description: 1 male and 1 female only, price: 0}, Female: {description: 1 female only, price: 0}, Male Stags: {description: 1 male only, price: 2000}}, tables: {Exclusive Table: {description: Exclusive table provided, price: 10000}, VIP Table: {decription: VIP table provided, price: 20000}}}, time: 19:00 - 01:30}}, images: [https://firebasestorage
I/flutter (25748): _eventdetail: {agelimit: 18+, date: Sat 7, Nov 2020, description: It's Club Night and the place will be exploding with amazing music
and your tapping on the floor. The party starts at 7 PM, so be there on 07th Nov and rejoice with Dj Manzee @amethhyyst!, dresscode: casuals, image: https://firebasestorage.googleapis.com/v0/b/guestinme-3aafb.appspot.com/o/places%2Famethhyyst%2Fevent%2F07112020_flyer.jpg?alt=media&token=967c8301-7730-40fb-98e4-1dfe07e7e5aa, lineup: [DJ Manzee], price: {crowd: {Couple: {description: 1 male and 1 female only, price: 0}, Female: {description: 1 female only, price: 0}, Male Stags: {description: 1 male only, price: 2000}}, tables: {Exclusive Table: {description: Exclusive table provided, price: 10000}, VIP Table: {decription: VIP table provided, price: 20000}}}, time: 19:00 - 01:30}
I/flutter (25748): _typeDetail: {Couple: {description: 1 male and 1 female only, price: 0}, Female: {description: 1 female only, price: 0}, Male Stags:
{description: 1 male only, price: 2000}}
I/flutter (25748): _typeSubDetail: {description: 1 male and 1 female only, price: 0}
I/flutter (25748): _typeSubDetail: {description: 1 female only, price: 0}
I/flutter (25748): _typeSubDetail: {description: 1 male only, price: 2000}
I/flutter (25748): _typeDetail: {Exclusive Table: {description: Exclusive table provided, price: 10000}, VIP Table: {decription: VIP table provided, price: 20000}}
I/flutter (25748): _typeSubDetail: {description: Exclusive table provided, price: 10000}
I/flutter (25748): _typeSubDetail: {decription: VIP table provided, price: 20000}
I/flutter (25748): NoSuchMethodError: The getter 'length' was called on null.
I/flutter (25748): Receiver: null
I/flutter (25748): Tried calling: length
我尝试了什么：我看到了一些关于此的帖子，并尝试通过初始化列表“[]”来删除对空对象的长度方法调用。我还设置了检查它们是否确实为空的 if 条件，因此我可以跳过该部分而不运行它（：null;）。
我的火力基地数据：
