flutter - 我可以根据给定值的变化从代码中更改滑块点吗?
问题描述
我移动一个滑块,我有一个值。是否有可能通过另一个小部件修改此值来修改滑块,以便该值与滑块本身之间始终存在对应关系?
我的意思是:例如,如果我将值增加 100,我也需要更改点滑块。
谢谢
解决方案
import 'package:flutter/material.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key, required this.title}) : super(key:
key);
final String title;
@override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
double sliderValue = 50;
@override
void initState() {
super.initState();
}
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.cyan,
appBar: AppBar(
title: Text(widget.title),
),
body: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Text(
'${sliderValue.toStringAsFixed(1)}',
style: TextStyle(color: Colors.white),
),
Slider(
value: sliderValue,
min: 0,
max: 100,
divisions: 100,
onChanged: (val) {
setState(() {
sliderValue = val;
});
},
),
Row(
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: [
ElevatedButton.icon(
onPressed: () {
setState(() {
if (sliderValue - 1 > -1) sliderValue -= 1;
});
},
icon: Icon(Icons.arrow_left),
label: Text('Decrease'),
),
ElevatedButton.icon(
onPressed: () {
setState(() {
if (sliderValue < 100.0) sliderValue += 1;
});
},
icon: Icon(Icons.arrow_right),
label: Text('Increase'),
)
],
)
],
),
);
}
}
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