首先确保将文件夹audioFiles拖到项目中以选择创建文件夹引用，它应该显示一个蓝色文件夹。

First make sure when you drag your folder audioFiles to your project to select create folder references and it should show a blue folder.

NSBundle方法pathForResource还有一个初始化程序，您可以在其中指定文件所在的目录：

Also NSBundle method pathForResource has an initialiser that you can specify in which directory your files are located:

let audioFileName = "audioName" 

if let audioFilePath = Bundle.main.path(forResource: audioFileName, ofType: "mp3", inDirectory: "audioFiles") {
    print(audioFilePath)
}

如果您想获取该文件URL，可以使用NSBundle方法URLForResource（withExtension：，子目录:)

If you would like to get that file URL you can use NSBundle method URLForResource(withExtension:, subdirectory:)

if let audioFileURL = Bundle.main.url(forResource: audioFileName, withExtension: "mp3", subdirectory: "audioFiles") {
    print(audioFileURL)
}