flutter - Flutter 中的背景音乐不起作用
问题描述
我正在尝试将背景音乐添加到我的应用程序中。如果我启动我的应用程序,音乐会正确开始,但如果我按下一个对音乐没有影响的按钮,音乐就会从新开始。我在 Flutter 中编码。这是我的代码,我把不重要的东西删掉了。
import 'package:audioplayers/audio_cache.dart';
import 'package:audioplayers/audioplayers.dart';
class _MyHomepageState extends State<MyHomepage> {
AudioPlayer player = AudioPlayer();
AudioCache cache = new AudioCache();
bool isPlaying = false;
Future<bool> _willPopCallback() async {
if (isPlaying == false) {
setState(() {
isPlaying = true;
});
player.stop();
}
return true;
}
openingActions() async {
player = await cache.loop('audio/test.mp3');
}
@override
Widget build(BuildContext context) {
openingActions();
return WillPopScope(
onWillPop: () => _willPopCallback(),
child: Scaffold(
body: Container(
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage('assets/images/background.jpg'),
fit: BoxFit.cover,
),
),
...
...
...
raisedbutton(
....
)
解决方案
您可以在下面复制粘贴运行完整代码
您可以openingActions();
从移动build
到initState
并且rebuild
不会openingActions();
再次调用
@override
void initState() {
openingActions();
super.initState();
}
@override
Widget build(BuildContext context) {
//openingActions(); //delete this line and move to initState
完整代码
import 'package:flutter/material.dart';
import 'package:audioplayers/audio_cache.dart';
import 'package:audioplayers/audioplayers.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
AudioPlayer player = AudioPlayer();
AudioCache cache = new AudioCache();
bool isPlaying = false;
Future<bool> _willPopCallback() async {
if (isPlaying == false) {
setState(() {
isPlaying = true;
});
player.stop();
}
return true;
}
openingActions() async {
player = await cache.loop('audio/test.mp3');
}
int _counter = 0;
void _incrementCounter() {
setState(() {
_counter++;
});
}
@override
void initState() {
openingActions();
super.initState();
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
RaisedButton(
child: Text('Open route'),
onPressed: () {
setState(() {});
},
),
Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headline4,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}
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