[移动开发]【Flutter】编写第一个 Flutter 应用（官方示例完整代码版）

基础步骤

第一步: 创建 Flutter app

第二步: 打开 /lib/main.dart，删除main.dart的所有代码，然后替换为下面的代码

第三步: 安装依赖程序 english_words

第四步: 启动应用

import 'package:english_words/english_words.dart';
import 'package:flutter/material.dart';

//文档
// https://flutter.cn/docs/get-started/codelab

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: '名称生成器',
      theme: new ThemeData(
        primaryColor: Colors.white,
      ),
      home: RandomWords(),
    );
  }
}

class RandomWords extends StatefulWidget {
  const RandomWords({Key? key}) : super(key: key);

  @override
  _RandomWordsState createState() => _RandomWordsState();
}

class _RandomWordsState extends State<RandomWords> {
  final _suggestions = <WordPair>[];
  final Set<WordPair> _saved = new Set<WordPair>();
  final _biggerFont = const TextStyle(fontSize: 18.0);

  Widget _buildSuggestions() {
    return ListView.builder(
        padding: const EdgeInsets.all(16.0),
        itemBuilder: (context, i) {
          if (i.isOdd) {
            return const Divider();
          }
          final index = i ~/ 2;
          if (index >= _suggestions.length) {
            _suggestions.addAll(generateWordPairs().take(10));
          }
          return _buildRow(_suggestions[index]);
        });
  }

  Widget _buildRow(WordPair pair) {
    final bool alreadySaved = _saved.contains(pair);
    return ListTile(
      title: Text(
        pair.asPascalCase,
        style: _biggerFont,
      ),
      trailing: new Icon(
        alreadySaved ? Icons.favorite : Icons.favorite_border,
        color: alreadySaved ? Colors.red : null,
      ),
      onTap: () {
        setState(() {
          if (alreadySaved) {
            _saved.remove(pair);
          } else {
            _saved.add(pair);
          }
        });
      },
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text("名称生成器"),
        actions: <Widget>[
          new IconButton(icon: const Icon(Icons.list), onPressed: _pushSaved),
        ],
      ),
      body: _buildSuggestions(),
    );
  }

  void _pushSaved() {
    Navigator.of(context).push(
      new MaterialPageRoute<void>(
        builder: (BuildContext context) {
          final Iterable<ListTile> tiles = _saved.map(
            (WordPair pair) {
              return new ListTile(
                title: new Text(
                  pair.asPascalCase,
                  style: _biggerFont,
                ),
              );
            },
          );

          final List<Widget> divided = ListTile.divideTiles(
            context: context,
            tiles: tiles,
          ).toList();

          return new Scaffold(
            appBar: new AppBar(
              title: const Text('收藏列表'),
            ),
            body: new ListView(children: divided),
          );
        },
      ),
    );
  }
}

将包依赖项添加到应用程序

1. 依赖它
   打开 pubspec.yaml 文件，然后在dependencies下添加english_words:
2. 安装它
   在 terminal中: 运行 flutter packages get
   或者
   在 IntelliJ中: 点击pubspec.yaml文件顶部的 ‘Packages Get’
3. 导入它
   在Dart代码中添加相应的import语句.

最终效果：

参考
https://flutter.cn/docs/get-started/codelab