public async Task <Stream> DownloadFile(int fileId)
{
var hubUrl = $"{GetHubUrlWithApiVersion()}/files/{fileId}";
var uri = new Uri(hubUrl);
return(await _restfulServiceClient.DownloadAsync(uri, null, await GetHMACHeader(uri)));
}
private async Task <Stream> RetrieveFile(string filePath)
{
var ext = Path.GetExtension(filePath);
if (ext != ".xls" && ext != ".xlsx")
{
throw new ArgumentException("Expected '.xls' or '.xlsx'", "selectedFile");
}
return(await _restfulServiceClient.DownloadAsync(new Uri(filePath)));
}