如何从 HttpResponseMessage 读取应用程序/pdf 内容类型并将其转换为 stream

Question

I have a Web API which connects to another end point. A GET method from the second Web API returns an application/pdf content-type. here I am successfully getting the data. How I can convert the response.Content to file/memory stream and return the value?

 public async Task<T> functionname<T>(ApplicationApiRoutes.APIRoutes route, string token = "", int TimeoutMinutes = 5, CancellationToken cancellationToken = default, params string[] routeparams)
    {
        T Response = default;
        try
        {
            ApplicationApiRoutes._RouteHashTable.TryGetValue(route, out string FormattedRoute);

            FormattedRoute = String.Format(FormattedRoute, routeparams);

            using (var request = new HttpRequestMessage(HttpMethod.Get, $"{FormattedRoute}"))
            {
                if (!String.IsNullOrWhiteSpace(token))
                {
                    request.Headers.Add("Cookie", $"access_token="+ token);
                }
                
               

                using (var response = await _httpclient
                    .SendAsync(request, HttpCompletionOption.ResponseHeadersRead, cancellationToken))
                {

                    
                   
                    response.EnsureSuccessStatusCode();

                    var result = await response.Content.ReadAsStringAsync();

                    Response = JsonConvert.DeserializeObject<T>(result, _jsonsettings);
                }
            }
        }
        catch (Exception ex)
        {
           
        }

        return Response;
    }

Answer 1

Assuming you want to download the file after retrieving it, try the following in your controller action method:

var fileStream = new MemoryStream();

using (var file = await _httpClient.GetStreamAsync(request).ConfigureAwait(false))
{
      await file.CopyToAsync(fileStream);
}

fileStream.Position = 0;  
return File(fileStream , "application/pdf", "filename.pdf");