我目前正在学习Flutter,我想创建动态的ToggleButtons
但我不知道为什么在单击ToggleButtons并滚动到底部后无法刷新。
这是代码的页面:
import 'dart:convert';
import 'package:flutter/material.dart';
class TestArea extends StatefulWidget {
@override
_TestArea createState() => _TestArea();
}
class _TestArea extends State<TestArea> {
List<List<bool>> boo=[[true,false,false],[true,false,false],[true,false,false],[true,false,false],[true,false,false],[true,false,false],[true,false,false],[true,false,false],[true,false,false],[true,false,false]];
var _myPets = List<Widget>();
int _index = 0;
void _add(String name) {
int keyValue = _index;
_myPets = List.from(_myPets)
..add(
Column(
children: <Widget>[
ListTile(
leading: Text(name),
),
Container(
alignment: Alignment.center,
margin: EdgeInsets.all(10),
padding: EdgeInsets.all(10),
child: ToggleButtons(
children: <Widget>[
Icon(Icons.ac_unit),
Icon(Icons.call),
Icon(Icons.cake),
],
onPressed: (int index) {
setState(() {
boo[keyValue][index] = !boo[keyValue][index];
});
},
isSelected: boo[keyValue],
),
)
],
));
setState(() => ++_index);
}
@override
void initState() {
// TODO: implement initState
super.initState();
for(int i=0;i<10;i++){
_add(i.toString());
}
}
@override
Widget build(BuildContext context) {
return Scaffold(
floatingActionButton: FloatingActionButton(
onPressed: () => print(json.encode(boo)),
child: Text('Save'),
),
appBar: AppBar(
title: Text('Add your pets'),
actions: <Widget>[
],
),
body: ListView(
children: _myPets,
),
);
}
}
还有一件事,我创建了更多美化ToggleButtons,但是它将显示错误。例如:
children: <Widget>[
Container(width: (MediaQuery.of(context).size.width - 49)/3, child: new Row(mainAxisAlignment: MainAxisAlignment.center, children: <Widget>[new Icon(Icons.whatshot,size: 16.0,color: Colors.red,),new SizedBox(width: 4.0,), new Text("滿意",style: TextStyle(color: Colors.red),)],)),
Container(width: (MediaQuery.of(context).size.width - 49)/3, child: new Row(mainAxisAlignment: MainAxisAlignment.center, children: <Widget>[new Icon(Icons.invert_colors,size: 16.0,color: Colors.yellow[800],),new SizedBox(width: 4.0,), new Text("要翻執",style: TextStyle(color: Colors.yellow[800]))],)),
Container(width: (MediaQuery.of(context).size.width - 49)/3, child: new Row(mainAxisAlignment: MainAxisAlignment.center, children: <Widget>[new Icon(Icons.ac_unit,size: 16.0,color: Colors.blue,),new SizedBox(width: 4.0,), new Text("翻執滿意",style: TextStyle(color: Colors.blue))],)),
],
谢谢! 最佳答案
您应该让切换按钮管理自己的状态。
import 'dart:convert';
import 'package:flutter/material.dart';
void main() {
runApp(MaterialApp(
home: TestArea(),
));
}
class TB extends StatefulWidget {
final List<bool> value;
final int keyValue;
final String name;
final Function onPressed;
TB(this.value, this.keyValue, {this.name, this.onPressed});
_TB createState() => _TB();
}
class _TB extends State<TB> {
Widget build(BuildContext context) {
return Column(
children: <Widget>[
ListTile(
leading: Text(widget.name ?? ""),
),
Container(
alignment: Alignment.center,
margin: EdgeInsets.all(10),
padding: EdgeInsets.all(10),
child: ToggleButtons(
children: <Widget>[
Icon(Icons.ac_unit),
Icon(Icons.call),
Icon(Icons.cake),
],
onPressed: (index) {
widget.onPressed(widget.keyValue, index);
setState(() {});
},
isSelected: widget.value,
),
)
],
);
}
}
class TestArea extends StatefulWidget {
@override
_TestArea createState() => _TestArea();
}
class _TestArea extends State<TestArea> {
List<List<bool>> boo = [
[true, false, false],
[true, false, false],
[true, false, false],
[true, false, false],
[true, false, false],
[true, false, false],
[true, false, false],
[true, false, false],
[true, false, false],
[true, false, false]
];
var _myPets = List<Widget>();
int _index = 0;
void _add(String name) {
_myPets.add(TB(boo[_index], _index, name: name, onPressed: _onPressed));
++_index;
}
void _onPressed(int key, int index) {
boo[key][index] = !boo[key][index];
}
@override
void initState() {
super.initState();
for (int i = 0; i < 10; i++) {
_add(i.toString());
}
}
@override
Widget build(BuildContext context) {
return Scaffold(
floatingActionButton: FloatingActionButton(
onPressed: () => print(json.encode(boo)),
child: Text('Save'),
),
appBar: AppBar(
title: Text('Add your pets'),
actions: <Widget>[],
),
body: ListView.builder(
itemCount: _myPets.length,
itemBuilder: (context, index) {
return _myPets[index];
},
),
);
}
}
关于flutter - 直到滚动到底部,屏幕才能实时更新,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/64493855/