flutter的ListView例子

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) {
// final wordPair = new WordPair.random(); return new MaterialApp( title: "Welcome to Flutter", theme: new ThemeData(primaryColor: Colors.white),
// home: new Scaffold(
// appBar: new AppBar(
// title: new Text("Welcome to Flutter"),
// ),
// body: new Center(
 child: new Text("Hello World!52"),
 child: new Text(wordPair.asPascalCase),
// child: new RandomWords(),
// ),
// ), home: new RandomWords(), );
  }
}

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

class RandomWordsState extends State<RandomWords> {
  final _suggestions = <WordPair>[];
  final _saved = new Set<WordPair>();
  final _biggerFont = const TextStyle(fontSize: 18.0); @override
  Widget build(BuildContext context) {
// final wordPair = new WordPair.random();
// return new Text(wordPair.asPascalCase) return new Scaffold( appBar: new AppBar( title: new Text("Startup Name Generator"), actions: <Widget>[ new IconButton(icon: new Icon(Icons.list), onPressed: _pushSaved) ], ), body: _buildSuggestions(), );
  } Widget _buildSuggestions() { return new ListView.builder( padding: const EdgeInsets.all(16.0), // 对每个建议的单词对都会调用一次itemBuilder，然后将单词对添加到ListTile中 // 在偶数行，为单词添加一个ListTile row // 在单数行，添加一个分割线Widget itemBuilder: (context, i) { if (i.isOdd) return new Divider(); // 语法 'i ~/ 2'表示i除以2，但返回值是整形（向下取整），如i，1，2，3，4，5，时 // 结果为0，1，1，2，2，这可以计算出ListView中减去分割线后的实际单词对数量 final index = i ~/ 2; if (index >= _suggestions.length) { // 如果是建议列表中最后一个单词对，则接着再生成10个单词对，然后加到建议列表中 _suggestions.addAll(generateWordPairs().take(10)); } return _buildRow(_suggestions[index]); }, );
  } Widget _buildRow(WordPair pair) { final alreadySaved = _saved.contains(pair); return new ListTile( title: new 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); } }); }, );
  } 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, ), ); }, ), );
  }

}


  

 

  
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文章来源: blog.csdn.net，作者：WongKyunban，版权归原作者所有，如需转载，请联系作者。

原文链接：blog.csdn.net/weixin_40763897/article/details/108203265