运行编写了一个listview代码简易的很(对着练),继承StatefulWidget(动态变化)方法
import 'package:flutter/material.dart';
import 'package:english_words/english_words.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return new MaterialApp (
title : 'Welcome',
home : new RandomWords(),
);
}
}
class RandomWords extends StatefulWidget {
@override
createState() => new RandomWordsState();
}
class RandomWordsState extends State <RandomWords> {
@override
final _suggestions = <WordPair>[];
final _saved = new Set<WordPair>();
final _biggerFont = const TextStyle(fontSize : 18.0);
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(title: new Text('ListView')),
body: _buildSuggestions(),
);
}
Widget _buildSuggestions() {
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 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);
}
});
},
);
}
}
跳转页面是经过路由进行跳转:
点击事件 onPressed
跳转:Navigator.of(context).push();
跳转代码 替换build:
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: const Text('Startup Name Generator'),
actions: <Widget>[
IconButton(icon: const Icon(Icons.list), onPressed: _pushSaved),
],
),
body: _buildSuggestions(),
);
}
_pushSaved方法:
void _pushSaved() {
Navigator.of(context).push(
MaterialPageRoute<void>(
builder: (BuildContext context) {
final Iterable<ListTile> tiles = _saved.map(
(WordPair pair) {
return ListTile(
title: Text(
pair.asPascalCase,
style: _biggerFont,
),
);
},
);
final List<Widget> divided = ListTile
.divideTiles(
context: context,
tiles: tiles,
)
.toList();
return Scaffold(
appBar: AppBar(
title: const Text('Saved Suggestions'),
),
body: ListView(children: divided),
);
},
),
);
}