How do I get the downloaded file name?

MikeRowley403

I have my app downloading a file using the DownloadManager, however if I take the pointer from the Enqueue method and pass it to GetUriForDownloadedFile I always get a null however the file downloads every time.

I need the downloaded file name as it may not always match the filename on the server as the DownloadManager appends a -# on the file if duplicates are downloaded. Any suggestions on how to get the downloaded file name so that I can pass it to a Send Intent?

Thanks
M

            Android.Net.Uri contentUri = Android.Net.Uri.Parse(uri);
            Android.App.DownloadManager.Request r = new Android.App.DownloadManager.Request(contentUri);
            r.SetDestinationInExternalPublicDir(Android.OS.Environment.DirectoryDownloads, filename);
            r.AllowScanningByMediaScanner();
            r.SetNotificationVisibility(Android.App.DownloadVisibility.VisibleNotifyCompleted);
            Android.App.DownloadManager dm = (Android.App.DownloadManager)Xamarin.Forms.Forms.Context.GetSystemService(Android.Content.Context.DownloadService);
            var savedFile = dm.GetUriForDownloadedFile(dm.Enqueue(r));

MikeRowley403

As is common with Xamarin Forums, I am answering my own question.
The solution is a bit convoluted, it appears you cannot get the URI for a downloaded file until the DownloadManager is done with the download. I solved my issue by catching the completed download in a BroadcastReceiver. DownloadIDsToShare is a List to ensure I don't fire the share intent on every downloaded file but only those where the user has clicked the Share Button.

    [BroadcastReceiver]
    [IntentFilter(new[] { DownloadManager.ActionDownloadComplete })]
    class BootCompletedBroadcastMessageReceiver : BroadcastReceiver
    {
        public override void OnReceive(Context context, Intent intent)
        {
            long dwnId = intent.GetLongExtra(DownloadManager.ExtraDownloadId, 0);
            if (MainActivity.CurrentActivity.DownloadIDsToShare.Contains(dwnId))
            {
                Android.App.DownloadManager dm = (Android.App.DownloadManager)Xamarin.Forms.Forms.Context.GetSystemService(Android.Content.Context.DownloadService);
                var fileURI = dm.GetUriForDownloadedFile(dwnId);
                var shareFile = new ShareFileService();
                shareFile.Share(fileURI.ToString());
            }
        }
    }

SirAndriy

good job @MikeRowley403!!!

PeerlessProgrammer

Very helpful @MikeRowley403

For others that would like more help I found a book through hours of searching that had a good explanation.
Xamarin Mobile Development for Android Cookbook!
https://books.google.com/books?id=3fSoCwAAQBAJ&pg=PA145#v=onepage&q&f=false

Hope that helps others that may be struggling.