来源

必备操作

引入网络请求库：
在项目的根目录下找到 pubspec.yaml 文件，
dependencies 里面加入

http: ^0.12.0

就可以在代码中引入网络请求库了：

import 'package:http/http.dart';

完整代码：

import 'dart:convert';
import 'package:http/http.dart' as http;
import 'package:flutter/material.dart';
import 'package:flutter/cupertino.dart';

class DoubanTheatersWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    return MaterialApp(
      title: "豆瓣电影",
      theme: ThemeData(
        primaryColor: Colors.redAccent,
      ),
      home: MyHomeApp(title: 'Movies',),
    );
  }
}

class MyHomeApp extends StatefulWidget {

  final String title;

  MyHomeApp({Key key, this.title}) : super(key: key);

  @override
  State<StatefulWidget> createState() {
    return _MyHomeAppState();
  }
}

class _MyHomeAppState extends State<MyHomeApp> {
  List subjects = [];
  String title = '';

  @override
  void initState() {
    super.initState();

    loadData();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(title),
      ),
      body: Center(
        child: getBody(),
      ),
    );
  }


  loadData() async {
    String loadURL = "https://api.douban.com/v2/movie/in_theaters";
    http.Response response = await http.get(loadURL);
    var result = json.decode(response.body);
    setState(() {
      title = result['title'];
      print('title: $title');
      subjects = result['subjects'];
    });
  }

  getItem(var subject) {
    var avatars = List.generate(subject['casts'].length, (int index) => Container(
      margin: EdgeInsets.only(left: index.toDouble() == 0.0 ? 0.0 : 16.0),
      child: CircleAvatar(
        backgroundColor: Colors.white10,
        backgroundImage: NetworkImage(
          subject['casts'][index]['avatars']['small']
        ),
      ),
    ));

    var row = Container(
      margin: EdgeInsets.all(4.0),
      child: Row(
        children: <Widget>[
          ClipRRect(
            borderRadius: BorderRadius.circular(4.0),
            child: Image.network(
              subject['images']['large'],
              width: 100.0, height: 150.0,
              fit: BoxFit.fill,
            ),
          ),
          Expanded(child: Container(
            margin: EdgeInsets.only(left: 8.0),
            height: 150.0,
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: <Widget>[
                Text(
                    subject['title'],
                  style: TextStyle(
                    fontWeight: FontWeight.bold,
                    fontSize: 20.0,
                  ),
                  maxLines: 1,
                ),
                Text(
                  "豆瓣评分: ${subject['rating']['average']}",
                  style: TextStyle(
                    fontSize: 16.0
                  ),
                ),
                Text(
                  "类型: ${subject['genres'].join('、')}"
                ),
                Text(
                  "导演: ${subject['directors'][0]['name']}"
                ),
                Container(
                  margin: EdgeInsets.only(top: 8.0),
                  child: Row(
                    children: <Widget>[
                      Text('主演：'),
                      Row(
                        children: avatars,
                      ),
                    ],
                  ),
                ),
              ],
            ),
          )),
        ],
      ),
    );
    return row;
  }

  getBody() {
    if (subjects.length != 0) {
      return ListView.builder(
        itemCount: subjects.length,
          itemBuilder: (BuildContext context, int position) {
            return getItem(subjects[position]);
          });
    } else {
      return CupertinoActivityIndicator();
    }
  }
}

main.dart:

import 'package:flutter/material.dart';

import 'DoubanTheaters.dart';

void main() {
  return runApp(DoubanTheatersWidget());
}