Flutter 颤振:致命错误:回调查找失败!(带音频播放器套装)
以下代码段是单击按钮时发出的短嘟嘟声:Flutter 颤振:致命错误:回调查找失败!(带音频播放器套装),flutter,dart,flutter-dependencies,flame,Flutter,Dart,Flutter Dependencies,Flame,以下代码段是单击按钮时发出的短嘟嘟声: FlatButton( onPressed: () => { final player = new AudioCache(); player.play('note1.wav'); } child: Text('Click to ding!'), ), 我面临的问题是,每当我单击此按钮时,尽管声音播放正确,但我在终端中收到此错误:flatter:Fatal error:Callback lookup failed 我想知道
FlatButton(
onPressed: () => {
final player = new AudioCache();
player.play('note1.wav');
}
child: Text('Click to ding!'),
),
我面临的问题是,每当我单击此按钮时,尽管声音播放正确,但我在终端中收到此错误:flatter:Fatal error:Callback lookup failed代码>
我想知道这是什么,我该怎么做
我查了一下,但没有发现任何有用的东西
谢谢我也遇到了同样的问题,所以这适用于我的游戏代码,我希望这适用于您,首先,创建如下控制器类:
import 'package:audioplayers/audio_cache.dart';
import 'package:audioplayers/audioplayers.dart';
void audioPlayerHandler(AudioPlayerState value) => print('state => $value');
class GameController {
static AudioPlayer audioPlayer = AudioPlayer();
static AudioCache audioCache = AudioCache();
static void play(String sound) {
if (!kIsWeb && Platform.isIOS) {
audioPlayer.monitorNotificationStateChanges(audioPlayerHandler);
}
audioCache.play(sound);
}
}
然后通过以下方式使用您的代码:
FlatButton(
onPressed: () => {
GameController.play('note1.wav');
}
child: Text('Click to ding!'),
),
看起来像是一个错误,如果没有通过monitorNotificationStateChanges
定义回调方法,则日志中会打印“致命错误:回调查找失败!”
这似乎没有任何影响
但避免这种情况的一种方法确实是设置回调,它必须在类之外定义,如下所示:
import 'package:audioplayers/audioplayers.dart';
class YourStatefulWidget extends StatefulWidget {
@override
_YourStatefulWidgetState createState() => _YourStatefulWidgetState();
}
class _YourStatefulWidgetState extends State<YourStatefulWidget> {
...
@override
void initState() {
super.initState();
if (Platform.isIOS) {
// to avoid getting "Fatal Error: Callback lookup failed!"
audioPlayer.monitorNotificationStateChanges(audioPlayerHandler);
}
}
...
}
// must be defined globally
void audioPlayerHandler(AudioPlayerState value) => null;
import'包:audioplayers/audioplayers.dart';
类YourStatefulWidget扩展StatefulWidget{
@凌驾
_YourStatefulWidgetState createState()=>\u YourStatefulWidgetState();
}
类_YourStatefulWidgetState扩展状态{
...
@凌驾
void initState(){
super.initState();
if(Platform.isIOS){
//避免获取“致命错误:回调查找失败!”
audioPlayer.monitorNotificationStateChanges(audioPlayerHandler);
}
}
...
}
//必须全局定义
void audioPlayerHandler(AudioPlayerState值)=>null;
谢谢,这就解决了问题。尽管我需要去掉扁平按钮上的花括号和分号。