private async Task <IStorageFile> CreateDownloadTask(string urltodownload, string filename, string fileextension, IProgress <DownloadBytesProgress> progessreporter)
{
IStorageFile file = null;
try
{
var knwonfolders = KnownFolders.Instance;
file = await knwonfolders.Downloads.CreateFile($"{filename}.{fileextension}", CreationCollisionOption.GenerateUniqueName);
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine(ex.StackTrace);
}
int receivedBytes = 0;
int totalBytes = 0;
WebClient client = new WebClient();
using (var stream = await client.OpenReadTaskAsync(urltodownload))
{
if (file != null)
{
// abrimos el archivo para escribirlo
var streamforwrite = await file.Open(FileAccessMode.Write);
// copiamos los datos del archivo
try
{
totalBytes = Int32.Parse(client.ResponseHeaders[HttpResponseHeader.ContentLength]);
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine(ex.StackTrace);
}
byte[] buffer = new byte[32768];
int read;
while ((read = await stream.ReadAsync(buffer, 0, buffer.Length)) > 0)
{
await streamforwrite.WriteAsync(buffer, 0, read);
receivedBytes += read;
if (progessreporter != null)
{
DownloadBytesProgress args = new DownloadBytesProgress(urltodownload, receivedBytes, totalBytes);
progessreporter.Report(args);
}
}
try { await streamforwrite.FlushAsync(); } catch (Exception ex) { System.Diagnostics.Debug.WriteLine(ex.StackTrace); }
try { streamforwrite.Dispose(); } catch (Exception ex) { System.Diagnostics.Debug.WriteLine(ex.StackTrace); }
}
/*
* byte[] buffer = new byte[4096];
* try
* {
* totalBytes = Int32.Parse(client.ResponseHeaders[HttpResponseHeader.ContentLength]);
* }
* catch(Exception ex)
* {
* System.Diagnostics.Debug.WriteLine(ex.StackTrace);
* }
* while (true)
* {
* int bytesRead = await stream.ReadAsync(buffer, 0, buffer.Length);
* if (bytesRead == 0)
* {
* await Task.Yield();
* break;
* }
* receivedBytes += bytesRead;
* if (progessreporter != null)
* {
* DownloadBytesProgress args = new DownloadBytesProgress(urltodownload, receivedBytes, totalBytes);
* progessreporter.Report(args);
* }
* }
*/
}
return(file);
}