html - Flutter，从网站获取特定图像

Question

我正在学习 flutter 并想获取各种图像，这些图像是卡通的缩略图。我使用了 HTTP 库并获取了响应数据。

但是，我该如何提取该图像？

网站:https://comic.naver.com/webtoon/weekdayList.nhn?week=

Future<http.Response> _getData() async {
    return await http.get('https://comic.naver.com/webtoon/weekdayList.nhn?week=');
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Colors.red,
      ),
      body: Center(
        child: RaisedButton(
          child: Text("Fetching"),
          onPressed: (){
            _getData().then((response){
              //dom.Document document = parser.parse(response.body);
              print(response.body);
            }).catchError((e) => print(e));
          },
        ),
      ),
    );
  }

---

What I want to do is below.

1. Fetching web page as HTML code
2. Find image url of each cartoon
3. Fetch that image

Answer 1

这里有一个基本示例，按下右上角的按钮后，您将在 ListView 中获取图像:

    import 'dart:async';
    import 'package:flutter/material.dart';
    import 'package:http/http.dart' as http;
    import 'package:html/parser.dart' as parser;
    import 'package:html/dom.dart' as dom;


   ...create your StatefulWidget



     class ParsingWidgetState extends State<ParsingWidget> {
      List<String> list = List();

      void _getData() async {
        final response =
            await http.get('https://comic.naver.com/webtoon/weekdayList.nhn?week=');
        dom.Document document = parser.parse(response.body);
        final elements = document.getElementsByClassName('thumb');

        setState(() {
          list = elements
              .map((element) =>
                  element.getElementsByTagName("img")[0].attributes['src'])
              .toList();
        });
      }

      @override
      Widget build(BuildContext context) {
        return Scaffold(
            appBar: AppBar(
              backgroundColor: Colors.red,
              actions: <Widget>[
                IconButton(
                  icon: Icon(Icons.refresh),
                  onPressed: () {
                    _getData();
                  },
                ),
              ],
            ),
            body: ListView.builder(
              itemCount: list.length,
              itemBuilder: (context, index) {
                return Image.network(
                  list[index],
                  height: 200.0,
                );
              },
            ));
      }
    }

尝试使用 FutureBuilder 而不是 setState，这只是一个工作示例。

更多信息:

• https://docs.flutter.io/flutter/widgets/FutureBuilder-class.html
• https://flutter-academy.com/async-in-flutter-futurebuilder/