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Image does not display in gallery after download

I am developing a Xamarin app which retrives info from DB, take/choose photo and upload them to remote server, display this images from the remote server and the user can delete them by tap on and press a button and download the images from the remote server to the local device.
Everything works without problem, but when I download the image and after I go to the gallery for check it, the image does not appear, whereas I can see it and open in the file explorer. When I reboot the phone, the image appear in the gallery.
Below my current button download method:
private void button_download_image_Clicked(object sender, EventArgs e)
{
Uri image_url_format = new Uri(image_url);
WebClient webClient = new WebClient();
try
{
byte[] bytes_image = webClient.DownloadData(image_url_format);
Stream image_stream = new MemoryStream(bytes_image);
string dest_folder = Android.OS.Environment.GetExternalStoragePublicDirectory(Android.OS.Environment.DirectoryDownloads).ToString();
string file_name = System.IO.Path.GetFileName(image_url_format.LocalPath);
string dest_path = System.IO.Path.Combine(dest_folder, file_name);
using (var fileStream = new FileStream(dest_path, FileMode.Create, FileAccess.Write))
{
image_stream.CopyTo(fileStream);
}
}
catch (Exception ex)
{
DisplayAlert("Error", ex.ToString(), "OK");
}
DisplayAlert("Alert", "Download completed!", "OK");
}
I tried in another device, but I got the same behavior.
Probably there is a sort of thing which does not refresh the gallery.
Any idea how to force the gallery to refresh or something similar?

You need to refresh your gallery after inserting or deleting any pictures in storage.
You can try this.
var mediaScanIntent = new Intent(Intent.ActionMediaScannerScanFile);
mediaScanIntent.SetData(Android.Net.Uri.FromFile(new Java.IO.File(dest_path)));
Xamarin.Forms.Forms.Context.SendBroadcast(mediaScanIntent);
Add these lines below your code.
Make it like
private void button_download_image_Clicked(object sender, EventArgs e)
{
Uri image_url_format = new Uri(image_url);
WebClient webClient = new WebClient();
try
{
byte[] bytes_image = webClient.DownloadData(image_url_format);
Stream image_stream = new MemoryStream(bytes_image);
string dest_folder = Android.OS.Environment.GetExternalStoragePublicDirectory(Android.OS.Environment.DirectoryDownloads).ToString();
string file_name = System.IO.Path.GetFileName(image_url_format.LocalPath);
string dest_path = System.IO.Path.Combine(dest_folder, file_name);
using (var fileStream = new FileStream(dest_path, FileMode.Create, FileAccess.Write))
{
image_stream.CopyTo(fileStream);
}
var mediaScanIntent = new Intent(Intent.ActionMediaScannerScanFile);
mediaScanIntent.SetData(Android.Net.Uri.FromFile(new Java.IO.File(dest_path)));
//for old xamarin forms version
Xamarin.Forms.Forms.Context.SendBroadcast(mediaScanIntent);
//for new xamarin forms version
//Android.App.Application.SendBroadcast(mediaScanIntent);
}
catch (Exception ex)
{
DisplayAlert("Error", ex.ToString(), "OK");
return;
}
DisplayAlert("Alert", "Download completed!", "OK");
}

You need to just refresh the file you have downloaded. It's helpful.
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT){
Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
File f = new File("file://"+ Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES));
Uri contentUri = Uri.fromFile(f);
mediaScanIntent.setData(contentUri);
this.sendBroadcast(mediaScanIntent);
}else{
sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://" + Environment.getExternalStorageDirectory())));
}

Make sure required permission given on both platforms.
Use in your class:
bool success = await DependencyService.Get<IPhotoLibrary>().SavePhotoAsync(data, folder, filename);
Common Interface
public interface IPhotoLibrary
{
Task<bool> SavePhotoAsync(byte[] data, string folder, string filename);
}
In Android service
public async Task<bool> SavePhotoAsync(byte[] data, string folder, string filename)
{
try
{
File picturesDirectory = Environment.GetExternalStoragePublicDirectory(Environment.DirectoryPictures);
File folderDirectory = picturesDirectory;
if (!string.IsNullOrEmpty(folder))
{
folderDirectory = new File(picturesDirectory, folder);
folderDirectory.Mkdirs();
}
using (File bitmapFile = new File(folderDirectory, filename))
{
bitmapFile.CreateNewFile();
using (FileOutputStream outputStream = new FileOutputStream(bitmapFile))
{
await outputStream.WriteAsync(data);
}
// Make sure it shows up in the Photos gallery promptly.
MediaScannerConnection.ScanFile(MainActivity.Instance,
new string[] { bitmapFile.Path },
new string[] { "image/png", "image/jpeg" }, null);
}
}
catch (System.Exception ex)
{
return false;
}
return true;
}
In iOS service:
public Task<bool> SavePhotoAsync(byte[] data, string folder, string filename)
{
NSData nsData = NSData.FromArray(data);
UIImage image = new UIImage(nsData);
TaskCompletionSource<bool> taskCompletionSource = new TaskCompletionSource<bool>();
image.SaveToPhotosAlbum((UIImage img, NSError error) =>
{
taskCompletionSource.SetResult(error == null);
});
return taskCompletionSource.Task;
}
also you can refer this one just to save an image and to reflect it in media, no need to use skiasharp for that. https://learn.microsoft.com/en-us/xamarin/xamarin-forms/user-interface/graphics/skiasharp/bitmaps/saving
Hope this may resolve your issue.

Refer to Blu's answer,
I changed this Xamarin.Forms.Forms.Context.SendBroadcast(mediaScanIntent); to Android.App.Application.Context.SendBroadcast(mediaScanIntent); and all works.

The process cannot access the file because it is being used by another process

I am running a program where a file gets uploaded to a folder in IIS,and then is processed to extract some values from it. I use a WCF service to perform the process, and BackgroundUploader to upload the file to IIS. However, after the upload process is complete, I get the error "The process cannot access the file x because it is being used by another process." Based on similar questions asked here, I gathered that the file concerned needs to be in a using statement. I tried to modify my code to the following, but it didn't work, and I am not sure if it is even right.
namespace App17
{
public sealed partial class MainPage : Page, IDisposable
{
private CancellationTokenSource cts;
public void Dispose()
{
if (cts != null)
{
cts.Dispose();
cts = null;
}
GC.SuppressFinalize(this);
}
public MainPage()
{
this.InitializeComponent();
cts = new CancellationTokenSource();
}
public async void Button_Click(object sender, RoutedEventArgs e)
{
try
{
Uri uri = new Uri(serverAddressField.Text.Trim());
FileOpenPicker picker = new FileOpenPicker();
picker.FileTypeFilter.Add("*");
StorageFile file = await picker.PickSingleFileAsync();
using (var stream = await file.OpenAsync(FileAccessMode.Read))
{
GlobalClass.filecontent = file.Name;
GlobalClass.filepath = file.Path;
BackgroundUploader uploader = new BackgroundUploader();
uploader.SetRequestHeader("Filename", file.Name);
UploadOperation upload = uploader.CreateUpload(uri, file);
await HandleUploadAsync(upload, true);
stream.Dispose();
}
}
catch (Exception ex)
{
string message = ex.ToString();
var dialog = new MessageDialog(message);
await dialog.ShowAsync();
Log(message);
}
}
private void CancelAll(object sender, RoutedEventArgs e)
{
Log("Canceling all active uploads");
cts.Cancel();
cts.Dispose();
cts = new CancellationTokenSource();
}
private async Task HandleUploadAsync(UploadOperation upload, bool start)
{
try
{
Progress<UploadOperation> progressCallback = new Progress<UploadOperation>(UploadProgress);
if (start)
{
await upload.StartAsync().AsTask(cts.Token, progressCallback);
}
else
{
// The upload was already running when the application started, re-attach the progress handler.
await upload.AttachAsync().AsTask(cts.Token, progressCallback);
}
ResponseInformation response = upload.GetResponseInformation();
Log(String.Format("Completed: {0}, Status Code: {1}", upload.Guid, response.StatusCode));
cts.Dispose();
}
catch (TaskCanceledException)
{
Log("Upload cancelled.");
}
catch (Exception ex)
{
string message = ex.ToString();
var dialog = new MessageDialog(message);
await dialog.ShowAsync();
Log(message);
}
}
private void Log(string message)
{
outputField.Text += message + "\r\n";
}
private async void LogStatus(string message)
{
var dialog = new MessageDialog(message);
await dialog.ShowAsync();
Log(message);
}
private void UploadProgress(UploadOperation upload)
{
BackgroundUploadProgress currentProgress = upload.Progress;
MarshalLog(String.Format(CultureInfo.CurrentCulture, "Progress: {0}, Status: {1}", upload.Guid,
currentProgress.Status));
double percentSent = 100;
if (currentProgress.TotalBytesToSend > 0)
{
percentSent = currentProgress.BytesSent * 100 / currentProgress.TotalBytesToSend;
}
MarshalLog(String.Format(CultureInfo.CurrentCulture,
" - Sent bytes: {0} of {1} ({2}%), Received bytes: {3} of {4}", currentProgress.BytesSent,
currentProgress.TotalBytesToSend, percentSent, currentProgress.BytesReceived, currentProgress.TotalBytesToReceive));
if (currentProgress.HasRestarted)
{
MarshalLog(" - Upload restarted");
}
if (currentProgress.HasResponseChanged)
{
MarshalLog(" - Response updated; Header count: " + upload.GetResponseInformation().Headers.Count);
}
}
private void MarshalLog(string value)
{
var ignore = this.Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, () =>
{
Log(value);
});
}
}
}
After this is done, the file name is sent to a WCF service which will access and process the uploaded file to extract certain values. It is at this point I receive the error. I would truly appreciate some help.
public async void Extract_Button_Click(object sender, RoutedEventArgs e)
{
ServiceReference1.Service1Client MyService = new ServiceReference1.Service1Client();
string filename = GlobalClass.filecontent;
string filepath = #"C:\Users\R\Documents\Visual Studio 2015\Projects\WCF\WCF\Uploads\"+ filename;
bool x = await MyService.ReadECGAsync(filename, filepath);
}
EDIT: Code before I added the using block
try
{
Uri uri = new Uri(serverAddressField.Text.Trim());
FileOpenPicker picker = new FileOpenPicker();
picker.FileTypeFilter.Add("*");
StorageFile file = await picker.PickSingleFileAsync();
GlobalClass.filecontent = file.Name;
GlobalClass.filepath = file.Path;
BackgroundUploader uploader = new BackgroundUploader();
uploader.SetRequestHeader("Filename", file.Name);
UploadOperation upload = uploader.CreateUpload(uri, file);
await HandleUploadAsync(upload, true);
}

When you work with stream writers you actually create a process, which you can close it from task manager. And after stream.Dispose() put stream.Close().
This should solve your problem.

You should also close the stream that writes the file to disk (look at your implementation of CreateUpload).

i got such error in DotNet Core 2 using this code:
await file.CopyToAsync(new FileStream(fullFileName, FileMode.Create));
counter++;
and this is how I managed to get rid of message (The process cannot access the file x because it is being used by another process):
using (FileStream DestinationStream = new FileStream(fullFileName, FileMode.Create))
{
await file.CopyToAsync(DestinationStream);
counter++;
}

BackgroundDownloader.CreateDownload method not working in windows phone 8.1

I'm trying to download a file with this code:
private async void Button_Click(object sender, RoutedEventArgs e)
{
try
{
Uri source;
Uri.TryCreate(txbUri.Text.Trim(),UriKind.Absolute, out source);
StorageFile destfile = await x.CreateFileAsync(Path.GetFileName(source.LocalPath), CreationCollisionOption.GenerateUniqueName);
BackgroundDownloader downloader = new BackgroundDownloader();
DownloadOperation download = await Task.Run(() => { return downloader.CreateDownload(source, destfile); });
await HandleDownloadAsync(download, true);
}
catch(Exception ex)
{
MessageBox.Show(ex.ToString());
}
}
but there is a exception on the line:
downloader.CreateDownload(source, destfile);
the exception is:
class not registered
I Compiled Microsoft sample with the exact codes and it worked fine. But I don't know why my App Doesn't.
Just in case "x" is a StorageFolder object that picked by user.

how to browse and upload files in Windows Phone App

How to upload a file in windows phone i mean which controls are used to browse the files (phone Content) are they pre-defined for windows phone or do we need to create manually. Browsing them and uploading them .

you can try the MSDN way
Make sure that the user has consented to the required scope, and then create an upload
Handle pending uploads when the app restarts.
private async void Upload()
{
try
{
// Ensure that the user has consented to the wl.skydrive and wl.skydrive_update scopes.
var authClient = new LiveAuthClient();
var authResult = await authClient.LoginAsync(new string[] { "wl.skydrive", "wl.skydrive_update" });
if (authResult.Session != null)
{
var liveConnectClient = new LiveConnectClient(authResult.Session);
// Upload to OneDrive.
LiveUploadOperation uploadOperation = await liveConnectClient.CreateBackgroundUploadAsync(
uploadPath, fileName, uploadInputStream, OverwriteOption.Rename);
LiveOperationResult uploadResult = await uploadOperation.StartAsync();
HandleUploadResult(uploadResult);
}
}
catch (LiveAuthException ex)
{
// Handle errors.
}
catch(LiveConnectException ex)
{
// Handle errors.
}
}
var pendingOperations = await LiveConnectClient.GetCurrentBackgroundUploadsAsync();
foreach(LiveDownloadOperation pendingOperation in pendingOperations)
{
try
{
var opResult = await pendingOperation.AttachAsync();
// Handle results.
}
catch
{
// Handle errors.
}
}

OneDrive file only uploads when app is terminated

I'm having a problem uploading a file to OneDrive from a universal app that I can't understand or figure out how to debug. I used this guide to go through the process of getting file IDs and such and it worked great until a few hours ago.
Now I can get folder and file ids, so I assume that I am still successfully connecting to OneDrive and my internet connection is still working. But when I step into the BackgroundUploadAsync the thread or whatever that was was executing before never returns. In the code below, the message "Uploading new file to OneDrive..." never disappears.
Strangely, while it is uploading I can refresh my OneDrive folder on ie and I'll never see what I'm trying to upload. But once I stop the debugger, or terminate the app on the phone, I can instantly refresh and the file will be there.
Here is the method for uploading:
public async Task UploadToOneDrive(string folderID, string localFileName)
{
try
{
StorageFile file = await ApplicationData.Current.LocalFolder.GetFileAsync(localFileName);
string fileName = "backup-" + DateTime.Now.ToString("dd-MM") + ".db";
await file.CopyAsync(ApplicationData.Current.LocalFolder, fileName, NameCollisionOption.ReplaceExisting);
file = await ApplicationData.Current.LocalFolder.GetFileAsync(fileName);
await connectClient.BackgroundUploadAsync(folderID,
fileName, file, OverwriteOption.Overwrite);
}
catch (LiveConnectException)
{
MessageDialog m = new MessageDialog("Could not connect to to OneDrive. Cloud sync will be stopped.");
m.ShowAsync();
}
catch (LiveAuthException)
{
MessageDialog m = new MessageDialog("Error authenticating OneDrive service. Please try cloud sync again later.");
m.ShowAsync();
}
catch (Exception ex)
{
MessageDialog m = new MessageDialog("Unknown exception occurred.\n\nError:{0}", ex.Message);
m.ShowAsync();
}
}
And here is the sync process
public async Task sync()
{
var sb = StatusBar.GetForCurrentView();
sb.ProgressIndicator.Text = "Syncing with OneDrive...";
await sb.ProgressIndicator.ShowAsync();
string cloudFolderID = await syncManager.CreateOrGetOneDriveFolderID("GlucoseCalculator", "Documents/");
string cloudFileID = await syncManager.GetFileID(DataManager.sqlFileName, "Documents/GlucoseCalculator/");
try
{
if (cloudFileID != null)
{
if (!(await dbManager.DoesFileExist(DataManager.sqlFileName)))
{
sb.ProgressIndicator.Text = "Downloading file from OneDrive...";
await syncManager.DownloadFromOneDrive(cloudFileID, DataManager.sqlFileName);
goto BREAK;
}
DateTime cloudLastEditDateTime = DateTime.Parse(await syncManager.GetFileProperty(cloudFileID, "updated_time"));
DateTime localLastEditDateTime = ApplicationData.Current.LocalFolder.GetFileAsync(DataManager.sqlFileName).GetResults().GetBasicPropertiesAsync().GetResults().DateModified.DateTime;
if (cloudLastEditDateTime > localLastEditDateTime)
{
sb.ProgressIndicator.Text = "Downloading file from OneDrive...";
await syncManager.DownloadFromOneDrive(cloudFileID, DataManager.sqlFileName);
}
else if (cloudLastEditDateTime < localLastEditDateTime)
{
sb.ProgressIndicator.Text = "Uploading file to OneDrive...";
await syncManager.UploadToOneDrive(cloudFolderID, DataManager.sqlFileName);
}
}
else if (cloudFileID == null)
{
sb.ProgressIndicator.Text = "Uploading new file to OneDrive...";
await syncManager.UploadToOneDrive(cloudFolderID, DataManager.sqlFileName);
}
}
catch (Exception)
{
sb.ProgressIndicator.Text = "Cloud synchronization failed.";
sb.ProgressIndicator.HideAsync();
return;
}
sb.ProgressIndicator.Text = "Synchronization complete!";
BREAK:;
await sb.ProgressIndicator.HideAsync();
}

Most likely, you are creating some object that implements IDisposible, but it is not in a using block. Maybe the StorageFile.