熟悉 Flutter 页面写法,编写第一个 Flutter App_熟悉了vue写法 再学flutter

根据文档实现第一个 Flutter 程序

文档中的情况是分为三个部分的，实现文字显示，再到实现一个列表。在 Step 2 里，实现了一个带赞的列表，并添加了点击菜单切换路由；
以下为实现了 Step 2 的代码：

lib/main.dart

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

import 'test/NameList.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Welcome to Flutter',
      theme: ThemeData(          // Add the 3 lines from here...
        primaryColor: Colors.cyan,
      ),
      home: Scaffold(
        body: RandomWords()
      ),
    );
  }
}

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lib/test/NameList.dart

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

class RandomWords extends StatefulWidget {
  @override
  _RandomWordsState createState() => _RandomWordsState();
}

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Startup Name Generator'),
        actions: [
          IconButton(icon: Icon(Icons.list), onPressed: _pushSaved),
        ],
      ),
      body: _buildSuggestions(),
    );
  }

  void _pushSaved() {
    Navigator.of(context).push(
      MaterialPageRoute<void>(
        // NEW lines from here...
        builder: (BuildContext context) {
          final tiles = _saved.map(
                (WordPair pair) {
              return ListTile(
                title: Text(
                  pair.asPascalCase,
                  style: _biggerFont,
                ),
              );
            },
          );
          final divided = ListTile.divideTiles(
            context: context,
            tiles: tiles,
          ).toList();

          return Scaffold(
            appBar: AppBar(
              title: Text('Saved Suggestions'),
            ),
            body: ListView(children: divided),
          );
        }, // ...to here.
      ),
    );
  }

  Widget _buildSuggestions() {
    return ListView.builder(
        padding: EdgeInsets.all(16.0),
        itemBuilder: /*1*/ (context, i) {
          if (i.isOdd) return Divider(); /*2*/

          final index = i ~/ 2; /*3*/
          if (index >= _suggestions.length) {
            _suggestions.addAll(generateWordPairs().take(10)); /*4*/
          }
          return _buildRow(_suggestions[index]);
        });
  }

  Widget _buildRow(WordPair pair) {
    final alreadySaved = _saved.contains(pair);

    return ListTile(
      title: Text(
        pair.asPascalCase,
        style: _biggerFont,
      ),
      trailing: Icon(   // NEW from here...
        alreadySaved ? Icons.favorite : Icons.favorite_border,
        color: alreadySaved ? Colors.red : null,
      ),
      onTap: () {      // NEW lines from here...
        setState(() {
          if (alreadySaved) {
            _saved.remove(pair);
          } else {
            _saved.add(pair);
          }
        });
      },
    );
  }
}
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这个 APP 的路由切换被 Debug 标签遮住了。。找了好一会才发现。。。

通过上述代码学习了

• 编写 Dart
• 使用热加载以获得更快的开发周期
• 实现一个有状态的小部件，向应用程序添加交互性
• 创建路由并添加逻辑，以便在主路由和新路由之间跳转
• 学习如何使用主题改变应用程序UI的外观

Step 1: https://flutter.dev/docs/get-started/codelab
Step 2: https://codelabs.developers.google.com/codelabs/first-flutter-app-pt2#0