我有以下型號：
class UserInfoModel {
String? image;
String? name;
String? country;
String? city;
String? position;
List<UserSkills>? userSkills;
UserInfoModel(
{this.image, this.name, this.country, this.position, this.userSkills});
UserInfoModel.fromJson(dynamic json) {
image = json['user_image'];
name = json['name'];
country = json['country'];
city = json['city'];
position = json['position'];
userSkills = [
for (final skill in json['skills'] ?? []) UserSkills.fromJson(skill),
];
}
Map<String, dynamic> toJson() {
final Map<String, dynamic> data = new Map<String, dynamic>();
data['user_image'] = this.image;
data['name'] = this.name;
data['country'] = this.country;
data['city'] = this.city;
data['position'] = this.position;
data['skills'] = [for (final skill in this.userSkills ?? []) skill.toJson()];
return data;
}
}
class UserSkills {
String? skillName;
String? skillPerc;
UserSkills({this.skillName, this.skillPerc});
UserSkills.fromJson(dynamic json) {
skillName = json['skill_name'];
skillPerc = json['skill_perc'];
}
Map<String, dynamic> toJson() {
final Map<String, dynamic> data = new Map<String, dynamic>();
data['skill_name'] = this.skillName;
data['skill_perc'] = this.skillPerc;
return data;
}
}
這與下圖消防商店有關：
我試圖創建兩種方法，一種讀取用戶資訊，另一種方法應該讀取用戶技能，所以這是我的以下代碼：
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:haroonpf/enums/screen_state.dart';
import 'package:haroonpf/presentation/screens/home/models/user_info.dart';
import 'package:haroonpf/utils/constants.dart';
import '../../base_view_model.dart';
class HomeViewModel extends BaseViewModel {
UserInfoModel? userModel;
List<UserSkills> userSkills = [];
void getUserData() async {
await FirebaseFirestore.instance
.collection('users')
.doc(uId)
.get()
.then((value) {
// print("fbValues: " value.data().toString());
userModel = UserInfoModel.fromJson(value.data());
}).catchError((error) {
print(error.toString());
});
setState(ViewState.Idle);
}
Future<List<UserSkills>> getUserSkills() async {
CollectionReference getSkills =
FirebaseFirestore.instance.collection('users');
await getSkills.get().then((snapshot) {
if (userSkills.isNotEmpty) userSkills.clear();
snapshot.docs.forEach((element) {
userSkills.add(UserSkills.fromJson(element.data()));
print("my skills:" element.data().toString());
});
});
setState(ViewState.Idle);
return userSkills;
}
}
所以在我的技能小部件類中，我嘗試檢索資料，如下代碼所示：
import 'package:flutter/material.dart';
import 'package:haroonpf/presentation/screens/home/viewmodel/home_view_model.dart';
import 'package:haroonpf/utils/animation/animated_progress_indicator.dart';
import 'package:haroonpf/utils/constants.dart';
import '../../../../../base_screen.dart';
class Skills extends StatelessWidget {
const Skills({
Key? key,
}) : super(key: key);
@override
Widget build(BuildContext context) {
return BaseScreen<HomeViewModel>(onModelReady: (homeViewModel) {
homeViewModel.getUserSkills();
}, builder: (context, homeViewModel, _) {
return Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Divider(),
Padding(
padding: const EdgeInsets.symmetric(vertical: defaultPadding),
child: Text(
"Framework out skills",
style: Theme.of(context).textTheme.subtitle2,
),
),
SingleChildScrollView(
scrollDirection: Axis.vertical,
child: Row(
children: [
...homeViewModel.userSkills.map(
(skills) => Expanded(
child: AnimatedCircularProgressIndicator(
percentage: double.parse(skills.skillPerc!),
label: skills.skillName.toString(),
),
),
),
],
),
),
],
);
});
}
}
但我發現了以下錯誤：
Unexpected null value.
所以似乎因為我沒有提到 doc id，因為我試圖添加 doc id 它不起作用......
那么如何AnimatedCircularProgressIndicator正確檢索技能資料呢？
uj5u.com熱心網友回復：
意外的空值。
你知道是哪一行導致了這個錯誤嗎？
我不確定我理解你HomeViewModel上課的方式。如果您修改getUserData為回傳 aFuture<UserInfoModel>那么您可以將它傳遞給FutureBuilder您的Skills小部件中的 a ：
class HomeViewModel extends BaseViewModel {
UserInfoModel? userModel;
Future<UserInfoModel> getUserData() async {
// not sure what setState does here but it was in the function to begin with
setState(ViewState.Idle);
// here I am returning a cached userModel.
// remove the following line of code if you don't actually want caching.
if (userModel != null) return userModel;
final value =
await FirebaseFirestore.instance.collection('users').doc(uId).get();
userModel = UserInfoModel.fromJson(value.data());
return userModel;
}
}
然后在您的Skills小部件中，創建FutureBuilder，然后List<UserSkills>在您的UserInfoModel.
class Skills extends StatelessWidget {
const Skills({
Key? key,
}) : super(key: key);
@override
Widget build(BuildContext context) {
return BaseScreen<HomeViewModel>(onModelReady: (homeViewModel) {
// homeViewModel.getUserSkills();
}, builder: (context, homeViewModel, _) {
return Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Divider(),
Padding(
padding: const EdgeInsets.symmetric(vertical: defaultPadding),
child: Text(
"Framework out skills",
style: Theme.of(context).textTheme.subtitle2,
),
),
FutureBuilder<UserInfoModel>(
future: homeViewModel.getUserData(),
builder: (context, snapshot) => SingleChildScrollView(
scrollDirection: Axis.vertical,
child: Row(
children: [
// loop over the skills to display each one
for (final skill in snapshot.data?.userSkills ?? [])
Expanded(
child: AnimatedCircularProgressIndicator(
percentage: double.parse(skill.skillPerc!),
label: skill.skillName.toString(),
),
),
],
),
),
),
],
);
});
}
}
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標籤：扑 镖 谷歌云firestore