访问flutter assets时出现File not Found异常

Question

我正在尝试编写一个插件来播放存储在 flutter 包的 assets 文件夹中的音频文件，并且这样做

if(call.method.equals("playMusic"))
{
    Log.d(TAG, "onMethodCall: play music function called");

    String fileLocation = call.argument("file");
    Log.d(TAG, "onMethodCall: file requested is "+fileLocation);
    AssetManager assetManager = registrar.context().getAssets();
    String key = registrar.lookupKeyForAsset(fileLocation);
    Log.d(TAG, "onMethodCall: key is "+key);
    AssetFileDescriptor fd;
    MediaPlayer mediaPlayer = new MediaPlayer();
    try {
        Log.d(TAG, "onMethodCall: found assets " + Arrays.toString(assetManager.list("assets/")));
        fd= assetManager.openFd(key);
        mediaPlayer.setDataSource(fd.getFileDescriptor(),fd.getStartOffset(),fd.getLength());
        fd.close();
        mediaPlayer.prepare();
        mediaPlayer.start();
        result.success("played successfully");
  }
  catch (Exception e){
    Log.d(TAG, "onMethodCall: exception occured "+e.toString());
    result.success("playing failed");
  }
}

fileLocation 正确传递为

assets/river.m4a

我查了一下，注册商查询的key是

flutter_assets/assets/river.m4a

并且文件存在于

的包中

assets/flutter_assets/assets/river.m4a

但是当我运行应用程序时它仍然抛出

D/TunePlugin: onMethodCall: exception occured java.io.FileNotFoundException: flutter_assets/assets/river.m4a

Answer 1

令我惊讶的是，当我运行通过终端使用相同的应用程序时，即 Git bash 它没有给我带来任何问题，而且歌曲播放没有任何错误。当我通过 android studio 运行同一个应用程序时，它会产生 FileNotFoundException

Answer 2

在你的 pubspec.yaml 文件中添加这个...

flutter:
    assets:
-assets/flutter_assets/assets/river.m4a

Answer 3

这通常发生在您尝试访问压缩文件时。

您可以将以下指令添加到位于 android/app/build.gradle 的 build.gradle：

aaptOptions {
    noCompress 'm4a'
}

访问flutter assets时出现File not Found异常

File not Found Exception occurs when accessing flutter assets

java

filenotfoundexception

dart

flutter