我想从 firestore 下载列表并在颤振小部件中显示为列表。数据已成功下载（由 print(cp.data() 证明）。
但是，显示的结果是[Instance of '_JsonQueryDocumentSnapshot']而不是实际的停车场数据。
任何人都可以帮助指出错误是什么。
谢谢
class DownloadDataScreen extends StatefulWidget {
@override
_DownloadDataScreen createState() => _DownloadDataScreen();
}
class _DownloadDataScreen extends State<DownloadDataScreen> {
List<DocumentSnapshot> carparkList = []; //List for storing carparks
void initState() {
super.initState();
readFromFirebase();
}
Future readFromFirebase() async {
// await FirebaseFirestore.instance
await FirebaseFirestore.instance
.collection('carpark')
.get()
.then((QuerySnapshot snapshot) {
snapshot.docs.forEach(
(DocumentSnapshot cp) {
carparkList.add(cp);
print('printing cp');
print(cp.data());
},
);
});
**return carparkList;**
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: new AppBar(
title: new Text(
'Car Park',
style: TextStyle(fontSize: 20, fontWeight: FontWeight.bold),
),
centerTitle: true,
),
body: FutureBuilder(
future: readFromFirebase(),
builder: (BuildContext context, AsyncSnapshot snapshot) {
List<Widget> children;
if (snapshot.hasData) {
children = <Widget>[
const Icon(
Icons.check_circle_outline,
color: Colors.green,
size: 60,
),
Padding(
padding: const EdgeInsets.only(top: 16),
child: Column(
children: [
Text('Result: ${snapshot.data}'),
],
),
)
];
} else if (snapshot.hasError) {
children = <Widget>[
const Icon(
Icons.error_outline,
color: Colors.red,
size: 60,
),
Padding(
padding: const EdgeInsets.only(top: 16),
child: Text('Error: ${snapshot.error}'),
)
];
} else {
children = const <Widget>[
SizedBox(
child: CircularProgressIndicator(),
width: 60,
height: 60,
),
Padding(
padding: EdgeInsets.only(top: 16),
child: Text('Awaiting result...'),
)
];
}
return Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: children,
),
);
},
),
);
}
}