Can I do a file upload to a web API using a web file as the source using streaming?

Question

Hi,

In C# rather than having to dowloading a file from the web using httpwebrequest, save this to file somewhere, and then upload to a webservice using a POST with the file as one of the parameters...

Can I instead somehow open a reader stream from httpwebresponse and then stream this into the http POST? Any code someone could post to show how?

In other words I'm trying to avoid haing to save to disk first.

Thanks

Answer 1

Something like that should do the trick :

HttpWebRequest downloadRequest = WebRequest.Create(downloadUri) as HttpWebRequest;
using(HttpWebResponse downloadResponse = downloadRequest.GetResponse() as HttpWebResponse)
{
    HttpWebRequest uploadRequest = new HttpWebRequest(uploadUri);
    uploadRequest.Method = "POST";
    uploadRequest.ContentLength = downloadResponse.ContentLength;
    using (Stream downloadStream = downloadResponse.GetResponseStream())
    using (Stream uploadStream = uploadRequest.GetRequestStream())
    {
        byte[] buffer = new byte[4096];
     int totalBytes = 0;
     while(totalBytes < downloadResponse.ContentLength)
     {
      int nBytes = downloadStream.Read(buffer, 0, buffer.Length);
      uploadStream.Write(buffer, 0, nBytes);
      totalBytes += nRead;
     }
    }
    HttpWebResponse uploadResponse = uploadRequest.GetResponse() as HttpWebResponse;
    uploadResponse.Close();
}

(untested code)