Task progress reporting

With TPL, we can use the IProgress<T> interface to get real-time progress notifications from the asynchronous operations. This can be used in scenarios where we need to update the user interface or the console app of asynchronous operations. When defining the TAP-based asynchronous methods, defining IProgress<T> in a parameter is optional. We can have overloaded methods that can help consumers to use in the case of specific needs. However, they should only be used if the asynchronous method supports them.  Here is the modified version of SaveFileAsync that updates the user about the real progress:

static void Main(string[] args) 
{ 
  var progressHandler = new Progress<string>(value => 
  { 
    Console.WriteLine(value); 
  }); 
 
  var progress = progressHandler as IProgress<string>; 
 
  CancellationTokenSource tokenSource = new CancellationTokenSource(); 
  CancellationToken token = tokenSource.Token; 
 
  Task.Factory.StartNew(() => SaveFileAsync(path, bytes, 
  token, progress)); 
  Console.Read(); 
 
} 
static Task<int> SaveFileAsync(string path, byte[] fileBytes, CancellationToken cancellationToken, IProgress<string> progress) 
{ 
  if (cancellationToken.IsCancellationRequested) 
  { 
    progress.Report("Cancellation is called"); 
    Console.WriteLine("Cancellation is requested..."); 
  } 
 
  progress.Report("Saving File"); 
  File.WriteAllBytes(path, fileBytes);   
  progress.Report("File Saved"); 
  return Task.FromResult<int>(0); 
 
}