编写第一个 Flutter App

编写第一个 Flutter App

终于这个时间来学习一下 Flutter 了

参考地址 : 第一个 Flutter App

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

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

class MyApp extends StatelessWidget {

  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    // return null;
    // final wordPair = new WordPair.random()
    return new MaterialApp(
      title: 'Startup Name Generator',
      home: new RandomWords(),
    );
  }
}

class RandomWords extends StatefulWidget {

  @override
  createState() => new RandomWordsState();

}

class RandomWordsState extends State {
  final _suggestions = [];
  final TextStyle _biggerFont = new TextStyle(fontSize: 18.0);

  final _saved = new Set();

  @override
  Widget build(BuildContext context) {

    return new Scaffold(
      appBar: new AppBar(
        title: new Text('Startup Name Generator'),
        actions: [
          new IconButton(icon: Icon(Icons.list), onPressed: _pushSaved)
        ],

      ),
      body: _buildSuggesstions(),
    );

  }

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

  Widget _buildRow(WordPair pair) {
    
    final aleradySaved = _saved.contains(pair);
    
    return new ListTile(
      title: new Text(
        pair.asPascalCase,
        style: _biggerFont,
      ),
      trailing: new Icon(
        aleradySaved ? Icons.favorite : Icons.favorite_border,
        color: aleradySaved ? Colors.red : null,

      ),

      onTap: () {
        setState(() {
          if (aleradySaved) {
            _saved.remove(pair);
          }else {
            _saved.add(pair);
          }
        });
      },

    );
  }

  // 跳转的动作
  void _pushSaved() {
    Navigator.of(context).push(
      new MaterialPageRoute(
        builder: (context) {
          final tiles = _saved.map(
                (pair) {
              return new ListTile(
                title: new Text(
                  pair.asPascalCase,
                  style: _biggerFont,
                ),
              );
            },
          );
          final divided = ListTile
              .divideTiles(
            context: context,
            tiles: tiles,
          )
              .toList();

          return new Scaffold(
            appBar: new AppBar(
              title: new Text(
                'Saved Suggestions'
              ),
            ),
            body: new ListView(children: divided),
          );
        },
      ),

    );
  }

}

在 iOS模拟器上面运行的结果, 如下图:

Simulator Screen Shot - iPhone 8 Plus - 2018-09-30 at 14.59.29.png

Simulator Screen Shot - iPhone 8 Plus - 2018-09-30 at 14.59.27.png