所以我使用以下代码从提供的URL下载.mp3歌曲:
private long DownloadData (Uri uri) {
long downloadReference;
// Create request for android download manager
downloadManager = (DownloadManager)getSystemService(DOWNLOAD_SERVICE);
DownloadManager.Request request = new DownloadManager.Request(uri);
request.setTitle("Data Download");
request.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI |
DownloadManager.Request.NETWORK_MOBILE);
request.setDescription("Android Data download using DownloadManager.");
request.setDestinationInExternalFilesDir(DownloadSongActivity.this,
Environment.DIRECTORY_DOWNLOADS ,"doesn'twork.mp3");
downloadReference = downloadManager.enqueue(request);
return downloadReference;
}
然后,我尝试使用以下代码为用户提供对这些文件的访问权限
File path = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).getAbsolutePath());
File[] downloadedFiles = path.listFiles();
if(downloadedFiles == null){
System.out.println("DownloadedFiles are null");
} else if(downloadedFiles.length == 0){
System.out.println("DownloadedFiles are empty");
} else{
System.out.println("DownloadedFiles are not empty");
}
然而,似乎downloadedFiles总是为空。有什么建议。 以下是一些图片供参考
如果我去文件 - >下载