Windows Store App HttpClient progress - http

Question

I need to provide the download progress inside the app for an arbitrary file.
I thought I could use HttpClient.GetInputStreamAsync progress but it is not fine grained. The progress notification is delivered very rare. The code below:
var httpClient = new HttpClient();
var path = new Uri(#"http://<path>");
using (var inputStream = (await httpClient.GetInputStreamAsync(path).AsTask(new MyProgress())).AsStreamForRead())
{
var outputFile = await ApplicationData.Current.TemporaryFolder.CreateFileAsync("output.mov", CreationCollisionOption.ReplaceExisting);
using (var outputStream = (await outputFile.OpenAsync(FileAccessMode.ReadWrite)).AsStreamForWrite())
{
await inputStream.CopyToAsync(outputStream);
await outputStream.FlushAsync();
}
}
Debug.WriteLine("done");
private class MyProgress : IProgress<HttpProgress>
{
public void Report(HttpProgress value)
{
Debug.WriteLine("HTTP {0} progress {1}/{2}", value.Stage, value.BytesReceived, value.TotalBytesToReceive);
}
}
outputs:
HTTP ResolvingName progress 0/
HTTP ConnectingToServer progress 0/
HTTP SendingHeaders progress 0/
HTTP WaitingForResponse progress 0/
HTTP ReceivingHeaders progress 0/
HTTP ReceivingContent progress 0/109192147
done
So at some point of time the total bytes to receive is known but no progress reported during file download.

Answer 1

I ended up with solution like below:
var httpClient = new HttpClient();
var path = new Uri(#"http://<path>");
var progressHelper = new ProgressHelper();
using (var inputStream = (await httpClient.GetInputStreamAsync(path).AsTask(progressHelper)).AsStreamForRead())
{
var outputFile = await ApplicationData.Current.TemporaryFolder.CreateFileAsync("output.mov", CreationCollisionOption.ReplaceExisting);
using (var outputStream = (await outputFile.OpenAsync(FileAccessMode.ReadWrite)).AsStreamForWrite())
{
var buffer = new byte[1024 * 1024];
int read;
while ((read = await inputStream.ReadAsync(buffer, 0, buffer.Length)) > 0)
{
progressHelper.BytesReceived += (ulong)read;
await outputStream.WriteAsync(buffer, 0, read);
}
await outputStream.FlushAsync();
}
}
Debug.WriteLine("done");
private class ProgressHelper : IProgress<HttpProgress>
{
private ulong _bytesReceived = 0;
private ulong? _totalBytesToReceive = null;
public void Report(HttpProgress value)
{
Debug.WriteLine("HTTP {0} progress {1}/{2}", value.Stage, value.BytesReceived, value.TotalBytesToReceive);
TotalBytesToReceive = value.TotalBytesToReceive;
}
public ulong? TotalBytesToReceive
{
get
{
return _totalBytesToReceive;
}
set
{
if (_totalBytesToReceive == value)
return;
_totalBytesToReceive = value;
UpdateProgress();
}
}
public ulong BytesReceived
{
get
{
return _bytesReceived;
}
set
{
if (_bytesReceived == value)
return;
_bytesReceived = value;
UpdateProgress();
}
}
public int? Progress
{
get
{
if (_totalBytesToReceive.HasValue)
{
return (int)Math.Round((100.0 * _bytesReceived) / _totalBytesToReceive.Value);
}
return null;
}
}
private void UpdateProgress()
{
Debug.WriteLine("Progress: {0}", Progress);
}
}

Answer 2

Since the HttpClient.GetInputStreamAsync doesn't support progress during file download, you can use other methods of HttpClient such as GetAsync andGetBufferAsync.The following code is updating of your code to use HttpClient.GetAsync.
var httpClient = new HttpClient();
var path = new Uri("https://sec.ch9.ms/slides/developerGuideToWindows10/02-XAMLcontrols.pptx");
HttpResponseMessage response = await httpClient.GetAsync(path).AsTask(new MyProgress());
using (Stream responseStream = (await response.Content.ReadAsInputStreamAsync()).AsStreamForRead())
{
var outputFile = await ApplicationData.Current.TemporaryFolder.CreateFileAsync("output.pptx", CreationCollisionOption.ReplaceExisting);
using (var outputStream = (await outputFile.OpenAsync(FileAccessMode.ReadWrite)).AsStreamForWrite())
{
await responseStream.CopyToAsync(outputStream);
await outputStream.FlushAsync();
}
}
Debug.WriteLine("done");
And the outputs