Flutter 更改ListView或ListWheelScrollView项目时如何实现轻微声音
我有一个非常简单的ListWheelScrollView,我在文本窗口小部件中将年份显示为元素,但对于UX来说,有轻微的项目更改声音是很好的Flutter 更改ListView或ListWheelScrollView项目时如何实现轻微声音,flutter,Flutter,我有一个非常简单的ListWheelScrollView,我在文本窗口小部件中将年份显示为元素,但对于UX来说,有轻微的项目更改声音是很好的 ListWheelScrollView( itemExtent: 80, onSelectedItemChanged: (int index) { setState(() { if (releaseEnd > i
ListWheelScrollView(
itemExtent: 80,
onSelectedItemChanged: (int index) {
setState(() {
if (releaseEnd > index + 1950) {
releaseStart = index + 1950;
} else {
return null;
}
});
},
diameterRatio: 4.0,
offAxisFraction: -3.0,
physics: BouncingScrollPhysics(),
children: years
.map((element) => RotatedBox(
quarterTurns: 3,
child: Container(
decoration: element == releaseStart
? BoxDecoration(
borderRadius: BorderRadius.all(
Radius.circular(4.0),
),
color: Colors.blue,
border: Border.all(
color: Colors.blue, width: 2),
shape: BoxShape.rectangle,
)
: null,
padding: EdgeInsets.all(5),
child: Text(
element.toString(),
textAlign: TextAlign.center,
style: Theme.of(context)
.textTheme
.subtitle
.copyWith(
color: element == releaseStart
? Colors.white
: Colors.black54,
letterSpacing: 2),
),
),
))
.toList(),
),
现在可以使用声音来更改其元素了吗?您可以使用声音从资源或url播放声音
在ListWheelScrollView中,当居中项目更改时,它将播放audio.mp3,因此,在onSelectedItemChanged中添加
audioCache.play('audio.mp3')
用于资产的示例代码段
import 'package:audioplayers/audio_cache.dart';
...
AudioCache audioCache = AudioCache();
...
_btn('Play', () => audioCache.play('audio.mp3')),
...
Widget _btn(String txt, VoidCallback onPressed) {
return ButtonTheme(minWidth: 48.0, child: RaisedButton(child: Text(txt), onPressed: onPressed));
}
完整代码
import 'dart:async';
import 'dart:io';
import 'package:audioplayers/audio_cache.dart';
import 'package:audioplayers/audioplayers.dart';
import 'package:flutter/material.dart';
import 'package:http/http.dart';
import 'package:path_provider/path_provider.dart';
import 'player_widget.dart';
typedef void OnError(Exception exception);
const kUrl1 = 'https://luan.xyz/files/audio/ambient_c_motion.mp3';
const kUrl2 = 'https://luan.xyz/files/audio/nasa_on_a_mission.mp3';
const kUrl3 = 'http://bbcmedia.ic.llnwd.net/stream/bbcmedia_radio1xtra_mf_p';
void main() {
runApp(new MaterialApp(home: new ExampleApp()));
}
class ExampleApp extends StatefulWidget {
@override
_ExampleAppState createState() => new _ExampleAppState();
}
class _ExampleAppState extends State<ExampleApp> {
AudioCache audioCache = AudioCache();
AudioPlayer advancedPlayer = AudioPlayer();
String localFilePath;
Future _loadFile() async {
final bytes = await readBytes(kUrl1);
final dir = await getApplicationDocumentsDirectory();
final file = File('${dir.path}/audio.mp3');
await file.writeAsBytes(bytes);
if (await file.exists()) {
setState(() {
localFilePath = file.path;
});
}
}
Widget _tab(List<Widget> children) {
return Center(
child: Container(
padding: EdgeInsets.all(16.0),
child: Column(
children: children.map((w) => Container(child: w, padding: EdgeInsets.all(6.0))).toList(),
),
),
);
}
Widget _btn(String txt, VoidCallback onPressed) {
return ButtonTheme(minWidth: 48.0, child: RaisedButton(child: Text(txt), onPressed: onPressed));
}
Widget remoteUrl() {
return SingleChildScrollView(
child: _tab([
Text(
'Sample 1 ($kUrl1)',
style: TextStyle(fontWeight: FontWeight.bold),
),
PlayerWidget(url: kUrl1),
Text(
'Sample 2 ($kUrl2)',
style: TextStyle(fontWeight: FontWeight.bold),
),
PlayerWidget(url: kUrl2),
Text(
'Sample 3 ($kUrl3)',
style: TextStyle(fontWeight: FontWeight.bold),
),
PlayerWidget(url: kUrl3),
Text(
'Sample 4 (Low Latency mode) ($kUrl1)',
style: TextStyle(fontWeight: FontWeight.bold),
),
PlayerWidget(url: kUrl1, mode: PlayerMode.LOW_LATENCY),
]),
);
}
Widget localFile() {
return _tab([
Text('File: $kUrl1'),
_btn('Download File to your Device', () => _loadFile()),
Text('Current local file path: $localFilePath'),
localFilePath == null ? Container() : PlayerWidget(url: localFilePath, isLocal: true),
]);
}
Widget localAsset() {
return _tab([
Text('Play Local Asset \'audio.mp3\':'),
_btn('Play', () => audioCache.play('audio.mp3')),
Text('Loop Local Asset \'audio.mp3\':'),
_btn('Loop', () => audioCache.loop('audio.mp3')),
Text('Play Local Asset \'audio2.mp3\':'),
_btn('Play', () => audioCache.play('audio2.mp3')),
Text('Play Local Asset In Low Latency \'audio.mp3\':'),
_btn('Play', () => audioCache.play('audio.mp3', mode: PlayerMode.LOW_LATENCY)),
Text('Play Local Asset In Low Latency \'audio2.mp3\':'),
_btn('Play', () => audioCache.play('audio2.mp3', mode: PlayerMode.LOW_LATENCY)),
getLocalFileDuration(),
]);
}
Future<int> _getDuration() async {
File audiofile = await audioCache.load('audio2.mp3');
await advancedPlayer.setUrl(
audiofile.path,
isLocal: true,
);
int duration = await Future.delayed(Duration(seconds: 2), () => advancedPlayer.getDuration());
return duration;
}
getLocalFileDuration() {
return FutureBuilder<int>(
future: _getDuration(),
builder: (BuildContext context, AsyncSnapshot<int> snapshot) {
switch (snapshot.connectionState) {
case ConnectionState.none:
return Text('No Connection...');
case ConnectionState.active:
case ConnectionState.waiting:
return Text('Awaiting result...');
case ConnectionState.done:
if (snapshot.hasError) return Text('Error: ${snapshot.error}');
return Text('audio2.mp3 duration is: ${Duration(milliseconds: snapshot.data)}');
}
return null; // unreachable
},
);
}
Widget notification() {
return _tab([
Text('Play notification sound: \'messenger.mp3\':'),
_btn('Play', () => audioCache.play('messenger.mp3', isNotification: true)),
]);
}
Widget advanced() {
return _tab([
Column(children: [
Text('Source Url'),
Row(children: [
_btn('Audio 1', () => advancedPlayer.setUrl(kUrl1)),
_btn('Audio 2', () => advancedPlayer.setUrl(kUrl2)),
_btn('Stream', () => advancedPlayer.setUrl(kUrl3)),
], mainAxisAlignment: MainAxisAlignment.spaceEvenly),
]),
Column(children: [
Text('Release Mode'),
Row(children: [
_btn('STOP', () => advancedPlayer.setReleaseMode(ReleaseMode.STOP)),
_btn('LOOP', () => advancedPlayer.setReleaseMode(ReleaseMode.LOOP)),
_btn('RELEASE', () => advancedPlayer.setReleaseMode(ReleaseMode.RELEASE)),
], mainAxisAlignment: MainAxisAlignment.spaceEvenly),
]),
new Column(children: [
Text('Volume'),
Row(children: [
_btn('0.0', () => advancedPlayer.setVolume(0.0)),
_btn('0.5', () => advancedPlayer.setVolume(0.5)),
_btn('1.0', () => advancedPlayer.setVolume(1.0)),
_btn('2.0', () => advancedPlayer.setVolume(2.0)),
], mainAxisAlignment: MainAxisAlignment.spaceEvenly),
]),
new Column(children: [
Text('Control'),
Row(children: [
_btn('resume', () => advancedPlayer.resume()),
_btn('pause', () => advancedPlayer.pause()),
_btn('stop', () => advancedPlayer.stop()),
_btn('release', () => advancedPlayer.release()),
], mainAxisAlignment: MainAxisAlignment.spaceEvenly),
]),
new Column(children: [
Text('Seek in milliseconds'),
Row(children: [
_btn('100ms', () => advancedPlayer.seek(Duration(milliseconds: 100))),
_btn('500ms', () => advancedPlayer.seek(Duration(milliseconds: 500))),
_btn('1s', () => advancedPlayer.seek(Duration(seconds: 1))),
_btn('1.5s', () => advancedPlayer.seek(Duration(milliseconds: 1500))),
], mainAxisAlignment: MainAxisAlignment.spaceEvenly),
]),
]);
}
@override
Widget build(BuildContext context) {
return DefaultTabController(
length: 5,
child: Scaffold(
appBar: AppBar(
bottom: TabBar(
tabs: [
Tab(text: 'Remote Url'),
Tab(text: 'Local File'),
Tab(text: 'Local Asset'),
Tab(text: 'Notification'),
Tab(text: 'Advanced'),
],
),
title: Text('audioplayers Example'),
),
body: TabBarView(
children: [remoteUrl(), localFile(), localAsset(), notification(), advanced()],
),
),
);
}
}
导入'dart:async';
导入“dart:io”;
导入“包:AudioPlayer/audio_cache.dart”;
导入“包:AudioPlayer/AudioPlayer.dart”;
进口“包装:颤振/材料.省道”;
导入“包:http/http.dart”;
导入“package:path_provider/path_provider.dart”;
导入“player_widget.dart”;
typedef void OnError(异常);
康斯特库尔https://luan.xyz/files/audio/ambient_c_motion.mp3';
康斯特库尔德酒店https://luan.xyz/files/audio/nasa_on_a_mission.mp3';
常数kUrl3=http://bbcmedia.ic.llnwd.net/stream/bbcmedia_radio1xtra_mf_p';
void main(){
runApp(新材料应用程序(主页:new ExampleApp());
}
类ExampleApp扩展StatefulWidget{
@凌驾
_ExampleAppState createState()=>新建_ExampleAppState();
}
类\u示例AppState扩展状态{
AudioCache AudioCache=AudioCache();
AudioPlayer advancedPlayer=AudioPlayer();
字符串localFilePath;
Future\u loadFile()异步{
最终字节=等待读取字节(kUrl1);
final dir=等待getApplicationDocumentsDirectory();
最终文件=文件('${dir.path}/audio.mp3');
等待文件。writeAsBytes(字节);
if(wait file.exists()){
设置状态(){
localFilePath=file.path;
});
}
}
小部件_选项卡(列出子项){
返回中心(
子:容器(
填充:所有边缘设置(16.0),
子:列(
children:children.map((w)=>Container(children:w,padding:EdgeInsets.all(6.0))).toList(),
),
),
);
}
小部件_btn(字符串txt,按下VoidCallback){
returnbuttontheme(minWidth:48.0,child:RaisedButton(child:Text(txt),onPressed:onPressed));
}
控件远程URL(){
返回SingleChildScrollView(
子项:_选项卡([
正文(
“样本1($kUrl1)”,
样式:TextStyle(fontWeight:fontWeight.bold),
),
PlayerWidget(url:kUrl1),
正文(
“样本2($kUrl2)”,
样式:TextStyle(fontWeight:fontWeight.bold),
),
PlayerWidget(url:kUrl2),
正文(
“样本3($kUrl3)”,
样式:TextStyle(fontWeight:fontWeight.bold),
),
PlayerWidget(url:kUrl3),
正文(
'示例4(低延迟模式)($kUrl1)',
样式:TextStyle(fontWeight:fontWeight.bold),
),
PlayerWidget(url:kUrl1,模式:PlayerMode.LOW_LATENCY),
]),
);
}
Widget localFile(){
返回选项卡([
Text('File:$kUrl1'),
_btn('Download File to your Device',()=>\u loadFile()),
Text('当前本地文件路径:$localFilePath'),
localFilePath==null?Container():PlayerWidget(url:localFilePath,isLocal:true),
]);
}
Widget localAsset(){
返回选项卡([
文本('Play Local Asset'audio.mp3\':'),
_btn('Play',()=>audioCache.Play('audio.mp3'),
文本('Loop Local Asset'audio.mp3\':'),
_btn('Loop',()=>audioCache.Loop('audio.mp3'),
文本('Play Local Asset'audio2.mp3\':'),
_btn('Play',()=>audioCache.Play('audio2.mp3'),
Text('Play Local Asset In Low Latency'audio.mp3\':'),
_btn('Play',()=>audioCache.Play('audio.mp3',模式:PlayerMode.LOW_LATENCY)),
Text('以低延迟播放本地资源'audio2.mp3\':'),
_btn('Play',()=>audioCache.Play('audio2.mp3',模式:PlayerMode.LOW_LATENCY)),
getLocalFileDuration(),
]);
}
Future\u getDuration()异步{
File audiofile=wait audioCache.load('audio2.mp3');
等待advancedPlayer.setUrl(
audiofile.path,
isLocal:是的,
);
int duration=wait Future.delayed(持续时间(秒数:2),()=>advancedPlayer.getDuration());
返回时间;
}
getLocalFileDuration(){
回归未来建设者(
未来:_getDuration(),
生成器:(BuildContext上下文,异步快照){
交换机(快照.连接状态){
案例连接状态。无:
返回文本('无连接…');
案例连接状态.active:
案例连接状态。正在等待:
返回文本('等待结果…');
案例连接状态。完成:
if(snapshot.hasError)返回文本('Error:${snapshot.Error}');
返回文本('audio2.mp3持续时间为:${duration(毫秒:snapshot.data)});
}
返回null;//不可访问
},
);
}
小部件通知(){
返回选项卡([
Text('播放通知声音:\'messenger.mp3\':'),
_btn('Play',()=>audioCache.Play('messenger.mp3',isNotification:true)),
]);
}
Widget advanced(){
返回选项卡([
栏(儿童:[
文本(“源Url”),
世界其他地区(儿童:[
_btn('Audio 1',()=>advancedPlayer.setUrl(kUrl1)),
_btn('Audio 2',()=>advancedPlayer.setUrl(kUrl2)),
_btn('Stream',()=>advancedPlayer.setUrl(kUrl3)),
],mainAxisAlignment:mainAxisAlignment.space),
]),
栏(儿童:[
文本(“释放模式”),
世界其他地区(儿童:[
_btn('STOP',()=>advancedPlayer.setReleaseMode(ReleaseMode.STOP)),
_btn('LOOP',()=>advancedPlayer.setReleaseMode(ReleaseMode.LOOP)),
_btn('RELEASE',()=>advancedPlayer.setReleaseMode(ReleaseMode.RELEASE)),
],mainAxisAlignment:mainAxisAlignment.space),
]),
新栏目(儿童:[
文本(“卷”),
世界其他地区(儿童:[
_btn('0.0',()=>advancedPlayer.setVolume(0.0)),
_