库dart:convert不导出显示名为“UTF8”的成员
我在dart:convert库中遇到错误 请帮我解决这个问题。这是我的代码块:库dart:convert不导出显示名为“UTF8”的成员,dart,flutter,Dart,Flutter,我在dart:convert库中遇到错误 请帮我解决这个问题。这是我的代码块: import 'dart:async' show Future, Stream; import 'dart:convert' show json, UTF8; import 'dart:io' show HttpClient; import 'package:http/http.dart' as http; import 'package:flutter/services.dart' show rootBundl
import 'dart:async' show Future, Stream;
import 'dart:convert' show json, UTF8;
import 'dart:io' show HttpClient;
import 'package:http/http.dart' as http;
import 'package:flutter/services.dart' show rootBundle;
/// PODO for questions
class Question {
String question;
bool answer;
Question.fromJson(Map jsonMap) :
question = jsonMap['question'],
answer = jsonMap['answer'];
String toString() {
return '$question is $answer';
}
}
Future<List<Question>> loadQuestionsLocally() async {
final jsonString = await rootBundle.loadString('assets/questions.json');
final questions = json.decode(jsonString);
return questions.map(
(q) => new Question.fromJson(q)
).toList();
}
Future<List<Question>> loadQuestionsNetwork() async {
final req = await new HttpClient().getUrl(
Uri.parse('https://raw.githubusercontent.com/mjohnsullivan/flutter_quiz/master/assets/questions.json')
);
final res = await req.close();
final body = await res.transform(UTF8.decoder).join();
final questions = json.decode(body);
return questions.map(
(q) => new Question.fromJson(q)
).toList();
}
........
我该怎么修这个?
谢谢 Dart 2中的名称更改为lowerCamelCase。看来你是照搬了一个老例子
使用utf8而不是utf8。Dart 2中的名称已更改为lowerCamelCase。看来你是照搬了一个老例子
使用utf8而不是utf8。是的,非常感谢!我试着在导入行改成小写的“utf8”,错误信息仍然存在。我试图更改整个文件。修好了!是的,非常感谢!我试着在导入行改成小写的“utf8”,错误信息仍然存在。我试图更改整个文件。修好了!
$ flutter --version
Flutter 1.2.1 • channel stable • https://github.com/flutter/flutter.git
Framework • revision 8661d8aecd (3 weeks ago) • 2019-02-14 19:19:53 -0800
Engine • revision 3757390fa4
Tools • Dart 2.1.2 (build 2.1.2-dev.0.0 0a7dcf17eb)