问题描述：

在使用 Media 插件时，如果保存路径设为 file.applicationStorageDirectory，则不能保存录音文件，不能触发任何 CALLBACK 或 PROMISE，外部路径 file.externalApplicationStorageDirectory 就没问题。

解决方案：

参考资料：

• https://github.com/ionic-team/ionic-native/issues/1610

具体步骤：

Just like what this guy <ihadeed> said:

• create new media file, enter file name only, not a full path. Example file.mp3
• record to the file
• stop recording
• wait a second or so (or wait for onStatusChange event to fire)
• now the file should be available at /sdcard/file.mp3... meaning you can retrieve it by calling this.file.resolveLocalFilesystemUrl(this.file.externalRootDirectory + 'file.mp3')
• you can now move the file elsewhere if you wish...