我可以在IOS中获得下载的M4A和MP3文件吗？

Question

我尝试下载音频文件（M4A），并想在我的应用程序中播放它，我成功完成了该操作，然后将其移至该应用程序的缓存文件夹中。当我从下载的位置播放该文件时，它只能运行一次，当我关闭该应用程序并重新打开它时，iOS不会在关闭该应用程序之前在保存该文件的URL上播放音频文件。如果我通过设备和模拟器导入容器，则表明该文件存在，但URL不起作用。我没有什么问题。请帮助

func getAudio () {
    if let audioUrl = songURL {

        // then lets create your document folder url
        let documentsDirectoryURL =  FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!

        // lets create your destination file url
        let destinationUrl = documentsDirectoryURL.appendingPathComponent(audioUrl.lastPathComponent)
        print(destinationUrl)

        // to check if it exists before downloading it
        if FileManager.default.fileExists(atPath: destinationUrl.path) {
            print("The file already exists at path")

            // if the file doesn't exist
        } else {
            // you can use NSURLSession.sharedSession to download the data asynchronously
            let urlSession = URLSession(configuration: .default, delegate: self, delegateQueue: OperationQueue())

            let downloadTask = urlSession.downloadTask(with: audioUrl)
            downloadTask.resume()
        }
    }
}

func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {
    print("downloadLocation:", location)
    // create destination URL with the original pdf name
    guard let url = downloadTask.originalRequest?.url else { return }
    let documentsPath = FileManager.default.urls(for: .libraryDirectory, in: .userDomainMask)[0]
    let destinationURL = documentsPath.appendingPathComponent(url.lastPathComponent)
    // delete original copy
    try? FileManager.default.removeItem(at: destinationURL)
    // copy from temp to Document
    do {
        try FileManager.default.copyItem(at: location, to: destinationURL)
        self.songURL = destinationURL
        self.downloaded = true
    } catch let error {
        print("Copy Error: \(error.localizedDescription)")
    }
}

下载文件后，我得到以下URL路径：file:///var/mobile/Containers/Data/Application/EDF4365C-59B4-4FCA-9E35-BF4FCD667134/Library/Caches/SoundHelix-Song-1.mp3

对于一个会话的应用程序运行正常（直到该应用程序处于活动状态）。

Answer 1

您无法将文件直接复制到.libraryDirectory，例如尝试尝试使用文档目录.documentDirectory

let documentsPath = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]

旁注，您真的需要使用您拥有的url变量吗？直接使用location

是否可行

let destinationURL = documentsPath.appendingPathComponent(location.lastPathComponent)