我试过了
Write Your First Flutter App, part 2 flutter app page 5
我现在对此应用程序有疑问。我想从该 List onLongPress 中删除一个条目,如下所示:
onLongPress: () {
setState(() {
_saved.remove(pair);
});
},
这将从列表中删除该项目,但不会更新屏幕。返回家中并重新打开此路线后,新项目没有被删除。但是如何在没有用户重新打开页面的情况下触发此页面上的更新。
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: 'Startup Name Generator',
home: RandomWords(),
theme: new ThemeData(
primaryColor: Colors.orange,
),
);
}
}
class RandomWords extends StatefulWidget {
@override
RandomWordsState createState() => RandomWordsState();
}
class RandomWordsState extends State<RandomWords> {
final List<WordPair> _suggestions = <WordPair>[];
final TextStyle _biggerFont = const TextStyle(fontSize: 18);
final Set<WordPair> _saved = new Set<WordPair>();
_buildSuggestions() {
return ListView.builder(
padding: const EdgeInsets.all(16),
itemBuilder: (context, i) {
if (i.isOdd) return 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: Text("Startup Name Generator"),
actions: <Widget>[
new IconButton(icon: const Icon(Icons.list), onPressed: _pushSaved),
],
),
body: _buildSuggestions(),
);
}
void _pushSaved() {
Navigator.of(context).push(
new MaterialPageRoute(
builder: (BuildContext context) {
final Iterable<ListTile> tiles = _saved.map(
(WordPair pair) {
return new ListTile(
//this is the delete operation
onLongPress: () {
setState(() {
_saved.remove(pair);
});
},
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('Saved Suggestions'),
),
body: new ListView(children: divided),
);
},
),
);
}
}
最佳答案
2019-11月最新方式
更多信息https://www.youtube.com/watch?v=iEMgjrfuc58
ListView.builder/GridView.builder(
itemBuilder: (BuildContext context, int index){
return Dismissible(
key: Key(selectServiceLocations[index].toString()),
onDismissed: (direction) {
setState(() {
selectServiceLocations.removeAt(index);
});
},
child: Container(...)
}
)
关于listview - 从 ListView 中 flutter 删除项目,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/55142992/