Android 必须向文本小部件提供非空字符串';包:flatter/src/widgets/text.dart';:断言失败:第360行位置10:';数据!=空';
抖动错误:必须向文本小部件提供非空字符串。”包:flatter/src/widgets/text.dart”:失败的断言:第360行第10位:“数据!”空' 引发了另一个异常:必须向文本小部件提供非空字符串 这是Main.dartAndroid 必须向文本小部件提供非空字符串';包:flatter/src/widgets/text.dart';:断言失败:第360行位置10:';数据!=空';,android,android-studio,flutter,dart,Android,Android Studio,Flutter,Dart,抖动错误:必须向文本小部件提供非空字符串。”包:flatter/src/widgets/text.dart”:失败的断言:第360行第10位:“数据!”空' 引发了另一个异常:必须向文本小部件提供非空字符串 这是Main.dart import 'package:bheekho_foundation/widgets/app.dart'; import 'package:flutter/material.dart'; void main() { runApp(App()); } impor
import 'package:bheekho_foundation/widgets/app.dart';
import 'package:flutter/material.dart';
void main() {
runApp(App());
}
import 'package:bheekho_foundation/screens/home.dart';
import 'package:flutter/material.dart';
class App extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
home: HomeScreen(),
);
}
}
import 'dart:convert';
import 'package:bheekho_foundation/models/request.dart';
import 'package:bheekho_foundation/services/request_service.dart';
import 'package:flutter/material.dart';
class HomeScreen extends StatefulWidget {
@override
_HomeScreenState createState() => _HomeScreenState();
}
class _HomeScreenState extends State<HomeScreen> {
RequestService _requestService = RequestService();
// ignore: unused_element
Future<List<Request>> _getAllRequest() async {
var result = await _requestService.getAllRequests();
List<Request> _list = List<Request>();
if (result != null) {
var requests = json.decode(result.body);
requests.forEach((request) {
var model = Request();
model.user_id = request['user_id'];
model.concern = request['concern'];
model.message = request['message'];
setState(() {
_list.add(model);
});
});
}
return _list;
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("Bheekho App"),
),
body: FutureBuilder<List<Request>>(
future: _getAllRequest(),
builder:
(BuildContext context, AsyncSnapshot<List<Request>> snapshot) {
if (snapshot.hasData) {
return ListView.builder(
itemCount: snapshot.data.length,
itemBuilder: (context, index) {
return Column(
children: [
Card(
child: Text(snapshot.data[index].user_id),
),
],
);
});
} else {
return Container(
child: Text('loading...'),
);
}
},
));
}
}
class Request {
// ignore: non_constant_identifier_names
int request_id;
// ignore: non_constant_identifier_names
String user_id;
String concern;
String message;
}
import 'package:bheekho_foundation/repository/repository.dart';
class RequestService {
Repository _repository;
RequestService() {
_repository = Repository();
}
getAllRequests() async {
return await _repository.httpGet('users');
}
}
import 'package:http/http.dart' as http;
class Repository {
String _baseUrl = "http://localhost:8000/api";
httpGet(String api) async {
return await http.get(_baseUrl + "/" + api);
}
}
这是飞镖应用程序
import 'package:bheekho_foundation/widgets/app.dart';
import 'package:flutter/material.dart';
void main() {
runApp(App());
}
import 'package:bheekho_foundation/screens/home.dart';
import 'package:flutter/material.dart';
class App extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
home: HomeScreen(),
);
}
}
import 'dart:convert';
import 'package:bheekho_foundation/models/request.dart';
import 'package:bheekho_foundation/services/request_service.dart';
import 'package:flutter/material.dart';
class HomeScreen extends StatefulWidget {
@override
_HomeScreenState createState() => _HomeScreenState();
}
class _HomeScreenState extends State<HomeScreen> {
RequestService _requestService = RequestService();
// ignore: unused_element
Future<List<Request>> _getAllRequest() async {
var result = await _requestService.getAllRequests();
List<Request> _list = List<Request>();
if (result != null) {
var requests = json.decode(result.body);
requests.forEach((request) {
var model = Request();
model.user_id = request['user_id'];
model.concern = request['concern'];
model.message = request['message'];
setState(() {
_list.add(model);
});
});
}
return _list;
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("Bheekho App"),
),
body: FutureBuilder<List<Request>>(
future: _getAllRequest(),
builder:
(BuildContext context, AsyncSnapshot<List<Request>> snapshot) {
if (snapshot.hasData) {
return ListView.builder(
itemCount: snapshot.data.length,
itemBuilder: (context, index) {
return Column(
children: [
Card(
child: Text(snapshot.data[index].user_id),
),
],
);
});
} else {
return Container(
child: Text('loading...'),
);
}
},
));
}
}
class Request {
// ignore: non_constant_identifier_names
int request_id;
// ignore: non_constant_identifier_names
String user_id;
String concern;
String message;
}
import 'package:bheekho_foundation/repository/repository.dart';
class RequestService {
Repository _repository;
RequestService() {
_repository = Repository();
}
getAllRequests() async {
return await _repository.httpGet('users');
}
}
import 'package:http/http.dart' as http;
class Repository {
String _baseUrl = "http://localhost:8000/api";
httpGet(String api) async {
return await http.get(_baseUrl + "/" + api);
}
}
这里是家。飞镖
import 'package:bheekho_foundation/widgets/app.dart';
import 'package:flutter/material.dart';
void main() {
runApp(App());
}
import 'package:bheekho_foundation/screens/home.dart';
import 'package:flutter/material.dart';
class App extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
home: HomeScreen(),
);
}
}
import 'dart:convert';
import 'package:bheekho_foundation/models/request.dart';
import 'package:bheekho_foundation/services/request_service.dart';
import 'package:flutter/material.dart';
class HomeScreen extends StatefulWidget {
@override
_HomeScreenState createState() => _HomeScreenState();
}
class _HomeScreenState extends State<HomeScreen> {
RequestService _requestService = RequestService();
// ignore: unused_element
Future<List<Request>> _getAllRequest() async {
var result = await _requestService.getAllRequests();
List<Request> _list = List<Request>();
if (result != null) {
var requests = json.decode(result.body);
requests.forEach((request) {
var model = Request();
model.user_id = request['user_id'];
model.concern = request['concern'];
model.message = request['message'];
setState(() {
_list.add(model);
});
});
}
return _list;
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("Bheekho App"),
),
body: FutureBuilder<List<Request>>(
future: _getAllRequest(),
builder:
(BuildContext context, AsyncSnapshot<List<Request>> snapshot) {
if (snapshot.hasData) {
return ListView.builder(
itemCount: snapshot.data.length,
itemBuilder: (context, index) {
return Column(
children: [
Card(
child: Text(snapshot.data[index].user_id),
),
],
);
});
} else {
return Container(
child: Text('loading...'),
);
}
},
));
}
}
class Request {
// ignore: non_constant_identifier_names
int request_id;
// ignore: non_constant_identifier_names
String user_id;
String concern;
String message;
}
import 'package:bheekho_foundation/repository/repository.dart';
class RequestService {
Repository _repository;
RequestService() {
_repository = Repository();
}
getAllRequests() async {
return await _repository.httpGet('users');
}
}
import 'package:http/http.dart' as http;
class Repository {
String _baseUrl = "http://localhost:8000/api";
httpGet(String api) async {
return await http.get(_baseUrl + "/" + api);
}
}
这是请求服务。dart
import 'package:bheekho_foundation/widgets/app.dart';
import 'package:flutter/material.dart';
void main() {
runApp(App());
}
import 'package:bheekho_foundation/screens/home.dart';
import 'package:flutter/material.dart';
class App extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
home: HomeScreen(),
);
}
}
import 'dart:convert';
import 'package:bheekho_foundation/models/request.dart';
import 'package:bheekho_foundation/services/request_service.dart';
import 'package:flutter/material.dart';
class HomeScreen extends StatefulWidget {
@override
_HomeScreenState createState() => _HomeScreenState();
}
class _HomeScreenState extends State<HomeScreen> {
RequestService _requestService = RequestService();
// ignore: unused_element
Future<List<Request>> _getAllRequest() async {
var result = await _requestService.getAllRequests();
List<Request> _list = List<Request>();
if (result != null) {
var requests = json.decode(result.body);
requests.forEach((request) {
var model = Request();
model.user_id = request['user_id'];
model.concern = request['concern'];
model.message = request['message'];
setState(() {
_list.add(model);
});
});
}
return _list;
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("Bheekho App"),
),
body: FutureBuilder<List<Request>>(
future: _getAllRequest(),
builder:
(BuildContext context, AsyncSnapshot<List<Request>> snapshot) {
if (snapshot.hasData) {
return ListView.builder(
itemCount: snapshot.data.length,
itemBuilder: (context, index) {
return Column(
children: [
Card(
child: Text(snapshot.data[index].user_id),
),
],
);
});
} else {
return Container(
child: Text('loading...'),
);
}
},
));
}
}
class Request {
// ignore: non_constant_identifier_names
int request_id;
// ignore: non_constant_identifier_names
String user_id;
String concern;
String message;
}
import 'package:bheekho_foundation/repository/repository.dart';
class RequestService {
Repository _repository;
RequestService() {
_repository = Repository();
}
getAllRequests() async {
return await _repository.httpGet('users');
}
}
import 'package:http/http.dart' as http;
class Repository {
String _baseUrl = "http://localhost:8000/api";
httpGet(String api) async {
return await http.get(_baseUrl + "/" + api);
}
}
这是存储库。dart
import 'package:bheekho_foundation/widgets/app.dart';
import 'package:flutter/material.dart';
void main() {
runApp(App());
}
import 'package:bheekho_foundation/screens/home.dart';
import 'package:flutter/material.dart';
class App extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
home: HomeScreen(),
);
}
}
import 'dart:convert';
import 'package:bheekho_foundation/models/request.dart';
import 'package:bheekho_foundation/services/request_service.dart';
import 'package:flutter/material.dart';
class HomeScreen extends StatefulWidget {
@override
_HomeScreenState createState() => _HomeScreenState();
}
class _HomeScreenState extends State<HomeScreen> {
RequestService _requestService = RequestService();
// ignore: unused_element
Future<List<Request>> _getAllRequest() async {
var result = await _requestService.getAllRequests();
List<Request> _list = List<Request>();
if (result != null) {
var requests = json.decode(result.body);
requests.forEach((request) {
var model = Request();
model.user_id = request['user_id'];
model.concern = request['concern'];
model.message = request['message'];
setState(() {
_list.add(model);
});
});
}
return _list;
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("Bheekho App"),
),
body: FutureBuilder<List<Request>>(
future: _getAllRequest(),
builder:
(BuildContext context, AsyncSnapshot<List<Request>> snapshot) {
if (snapshot.hasData) {
return ListView.builder(
itemCount: snapshot.data.length,
itemBuilder: (context, index) {
return Column(
children: [
Card(
child: Text(snapshot.data[index].user_id),
),
],
);
});
} else {
return Container(
child: Text('loading...'),
);
}
},
));
}
}
class Request {
// ignore: non_constant_identifier_names
int request_id;
// ignore: non_constant_identifier_names
String user_id;
String concern;
String message;
}
import 'package:bheekho_foundation/repository/repository.dart';
class RequestService {
Repository _repository;
RequestService() {
_repository = Repository();
}
getAllRequests() async {
return await _repository.httpGet('users');
}
}
import 'package:http/http.dart' as http;
class Repository {
String _baseUrl = "http://localhost:8000/api";
httpGet(String api) async {
return await http.get(_baseUrl + "/" + api);
}
}
您的快照。数据[索引]。此时,用户id很可能为空。 为了确保不将null分配给文本小部件,可以将其更改为如下内容:
Text(
snapshot.data[index].user_id != null
? snapshot.data[index].user_id
: ""
)
这实际上检查数据是否为空,如果不是空,则加载快照数据。如果是,则加载一个空字符串