Pfthb

I'm working on a .Net core solution that takes backup of storage files from another microservice and because this process takes too long time, we decided to build this routine under a background task.By following this link:
https://docs.microsoft.com/en-us/aspnet/core/fundamentals/host/hosted-services?view=aspnetcore-2.1
I have implemented the background by using Queued background tasks like the following :

 public interface IBackgroundTaskQueue
 
 void QueueBackgroundWorkItem(Func<CancellationToken, Task> workItem);

 Task<Func<CancellationToken, Task>> DequeueAsync(
 CancellationToken cancellationToken);
 

 public class BackgroundTaskQueue : IBackgroundTaskQueue
 
 private ConcurrentQueue<Func<CancellationToken, Task>> _workItems =
 new ConcurrentQueue<Func<CancellationToken, Task>>();
 private SemaphoreSlim _signal = new SemaphoreSlim(0);

 public void QueueBackgroundWorkItem(
 Func<CancellationToken, Task> workItem)
 
 if (workItem == null)
 
 throw new ArgumentNullException(nameof(workItem));
 

 _workItems.Enqueue(workItem);
 _signal.Release();
 

 public async Task<Func<CancellationToken, Task>> DequeueAsync(
 CancellationToken cancellationToken)
 
 await _signal.WaitAsync(cancellationToken);
 _workItems.TryDequeue(out var workItem);

 return workItem;
 
 

 public class QueuedHostedService : BackgroundService
 
 private readonly ILogger _logger;

 public QueuedHostedService(IBackgroundTaskQueue taskQueue,
 ILoggerFactory loggerFactory)
 
 TaskQueue = taskQueue;
 _logger = loggerFactory.CreateLogger<QueuedHostedService>();
 

 public IBackgroundTaskQueue TaskQueue get; 

 protected async override Task ExecuteAsync(
 CancellationToken cancellationToken)
 
 _logger.LogInformation("Queued Hosted Service is starting.");

 while (!cancellationToken.IsCancellationRequested)
 
 var workItem = await TaskQueue.DequeueAsync(cancellationToken);

 try
 
 await workItem(cancellationToken);
 
 catch (Exception ex)
 
 _logger.LogError(ex,
 $"Error occurred executing nameof(workItem).");
 
 

 _logger.LogInformation("Queued Hosted Service is stopping.");
 
 

}

and in the controller action method I did that:

 [HttpPost]
 [ValidateAntiForgeryToken]
 public IActionResult TakeBackup()
 
 // Process #1: update latest backup time in setting table.
 var _setting = _settingService.FindByKey("BackupData");
 var data = JsonConvert.DeserializeObject<BackUpData>(_setting.Value);
 data.LatestBackupTime = DateTime.UtcNow;
 _setting.Value = JsonConvert.SerializeObject(data);
 _settingService.AddOrUpdate(_setting);

 // Process #2: Begin a background service to excaute the backup task.

 _queue.QueueBackgroundWorkItem(async token =>
 
 // instead of this staff I will replace by the API I want to consume.
 var guid = Guid.NewGuid().ToString();

 for (int delayLoop = 0; delayLoop < 3; delayLoop++)
 
 _logger.LogInformation(
 $"Queued Background Task guid is running. delayLoop/3");
 await Task.Delay(TimeSpan.FromSeconds(5), token);
 

 _logger.LogInformation(
 $"Queued Background Task guid is complete. 3/3");

// Here I need to redirect to the index view after the task is finished (my issue) ..
 RedirectToAction("Index",new progress="Done");
 );

 return RedirectToAction("Index");
 


 }

The logger information displays successfully
All what I need is to find away to be able to reload the index controller after the background task is done successfully but for some reason I don't know it can't be redirected.

The Index action method is like that :

public async Task<IActionResult> Index()

 var links = new List<LinkObject>();
 var files = await _storageProvider.GetAllFiles(null, "backup");
 foreach (var f in files)
 
 var file = f;
 if (f.Contains("/devstoreaccount1/"))
 
 file = file.Replace("/devstoreaccount1/", "");
 
 file = file.TrimStart('/');
 links.Add(new LinkObject()
 
 Method = "GET",
 Href = await _storageProvider.GetSasUrl(file),
 Rel = f
 );
 
 return View(links);

Thanks !