无法加载资产：加载 .mp3 文件时出错 Flutter答案

【问题标题】：Unable to load asset: error when loading an .mp3 file Flutter无法加载资产：加载 .mp3 文件时出错 Flutter
【发布时间】：2020-04-07 16:26:07
【问题描述】：

我正在使用 audioplayers 包向我的应用程序添加声音，但最初构建时没有播放声音。在加载文件时热重启面团后，我得到了这个异常：

E/flutter (32175): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: Unable to load asset: assets/assets/click.mp3
E/flutter (32175): #0      PlatformAssetBundle.load (package:flutter/src/services/asset_bundle.dart:221:7)
E/flutter (32175): <asynchronous suspension>
E/flutter (32175): #1      AudioCache._fetchAsset (package:audioplayers/audio_cache.dart:60:29)
E/flutter (32175): #2      AudioCache.fetchToMemory (package:audioplayers/audio_cache.dart:67:30)
E/flutter (32175): <asynchronous suspension>
E/flutter (32175): #3      AudioCache.load (package:audioplayers/audio_cache.dart:82:37)
E/flutter (32175): #4      AudioCache.getAbsoluteUrl (package:audioplayers/audio_cache.dart:140:23)
E/flutter (32175): #5      AudioCache.play (package:audioplayers/audio_cache.dart:103:24)
E/flutter (32175): #6      _MapScreenState.build.<anonymous closure> (package:fixit_cloud_biking/Screens/map_screen.dart:1239:46)
E/flutter (32175): #7      _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:706:14)
E/flutter (32175): #8      _InkResponseState.build.<anonymous closure> (package:flutter/src/material/ink_well.dart:789:36)
E/flutter (32175): #9      GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:182:24)
E/flutter (32175): #10     TapGestureRecognizer.handleTapUp (package:flutter/src/gestures/tap.dart:486:11)
E/flutter (32175): #11     BaseTapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:264:5)
E/flutter (32175): #12     BaseTapGestureRecognizer.handlePrimaryPointer (package:flutter/src/gestures/tap.dart:199:7)
E/flutter (32175): #13     PrimaryPointerGestureRecognizer.handleEvent (package:flutter/src/gestures/recognizer.dart:467:9)
E/flutter (32175): #14     PointerRouter._dispatch (package:flutter/src/gestures/pointer_router.dart:76:12)
E/flutter (32175): #15     PointerRouter._dispatchEventToRoutes.<anonymous closure> (package:flutter/src/gestures/pointer_router.dart:117:9)
E/flutter (32175): #16     _LinkedHashMapMixin.forEach (dart:collection-patch/compact_hash.dart:379:8)
E/flutter (32175): #17     PointerRouter._dispatchEventToRoutes (package:flutter/src/gestures/pointer_router.dart:115:18)
E/flutter (32175): #18     PointerRouter.route (package:flutter/src/gestures/pointer_router.dart:101:7)
E/flutter (32175): #19     GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:218:19)
E/flutter (32175): #20     GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:198:22)
E/flutter (32175): #21     GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:156:7)
E/flutter (32175): #22     GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:102:7)
E/flutter (32175): #23     GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:86:7)
E/flutter (32175): #24     _rootRunUnary (dart:async/zone.dart:1138:13)
E/flutter (32175): #25     _CustomZone.runUnary (dart:async/zone.dart:1031:19)
E/flutter (32175): #26     _CustomZone.runUnaryGuarded (dart:async/zone.dart:933:7)
E/flutter (32175): #27     _invoke1 (dart:ui/hooks.dart:273:10)
E/flutter (32175): #28     _dispatchPointerDataPacket (dart:ui/hooks.dart:182:5)
E/flutter (32175):

我确实将文件放在包含我用于图标的所有图像的同一资产文件夹中，因此pubspec.yaml 文件中的缩进是正确的。问题不应该是文件命名，因为我使用驼峰式命名或单个单词命名（从带有空格的图像命名中学到的教训..）。值得一提的是，如果我将文件拖放到assets文件夹中，我会收到错误消息。我尝试删除文件夹，重新创建它，然后拖放工作，但只有一次..第二次添加的文件会引发错误。这是应该播放声音的按钮：

IconButton(
                        icon: Image.asset('assets/centerMapButton.png'),
                        iconSize: 60,
                        onPressed: () async {
                          await widget.cache.play('assets/click.mp3',
                              volume: 50, mode: PlayerMode.MEDIA_PLAYER);
                          print('Center map button pressed');
                          _mapController.move(userLocation, 16);
                        }),

并且AudioCache()被声明为AudioCache cache = new AudioCache();。

【问题讨论】：

第二次添加文件后，您是否重新启动（通过停止并重新启动）您的应用
我尝试了应用程序正在运行和未运行的时间。我确实解决了文件加载问题，因为事实证明不必指定路径，因为插件直接查看资产文件夹。 play('assets/click.mp3') 是错误的，play('click.mp3') works as expected.. I did noticed from the error Unable to load assets: assets/assets/click.mp3` 'assets/' 出现了两次，所以我尝试省略它并且它起作用了。我仍然必须解决拖放文件添加问题，因为使用 finder 复制它们可以工作，但显然有问题..
这真的很奇怪
是的..我将尝试将项目文件夹移动到不同的驱动器上，看看是否有什么不同..
@Vincenzo 这实际上是设计使然。您可以在此处阅读文档：github.com/luanpotter/audioplayers/blob/master/doc/…

标签： flutter assets

【解决方案1】：

尝试更改此设置资产/点击.mp3 至点击.mp3

我在忽略路径中的“assets/”时遇到了同样的错误，它会从本地无缝播放声音。 Audioplayers 假设它的默认路径是 assets/

【讨论】：

嗨。欢迎并感谢您的回答。幸运的是，我确实发现了这一点，并且感谢 MidhumMP 评论，我明白了原因。再次感谢并欢迎加入社区。span>

【解决方案2】：

如果您未在 pubspec.yaml 中设置资产位置，just_audio 中可能会发生这种情况。

flutter:
  assets:
    - audio/

这告诉 Flutter 您在项目的根目录中有一个 audio 文件夹，用于保存音频资产。

完成之后，您应该能够设置资产并像这样播放它：

await player.setAsset('audio/cow.mp3');
player.play();

如果您在路径中拼写错误，也会发生该错误，但我假设您已经检查过了。

【讨论】：

【解决方案3】：

清除资产文件夹对我有用：

await AudioPlayer.clearAssetCache();

清除插件的内部资产缓存目录。什么时候调用这个应用程序的资产已更改以强制重新获取资产资产包。

【讨论】：