Uploading an attachment in C# URGENT

[Vaishali Dhanoa]

Hey! I have been trying to upload an attachment( text or png) to my confluence page, but it is giving me an error. I am trying to send the request in the following format. Please let me know if it requires some changes?
 This is the code snippet in C# : 

string boundary = "------------------------" + DateTime.Now.Ticks.ToString("x");
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
req.Credentials = CredentialCache.DefaultCredentials;
req.Headers.Add("X-Atlassian-Token", "nocheck");
req.Method = "POST";
req.ContentType = "multipart/form-data; boundary=" + boundary;
string contentDisp = "Content-Disposition: form-data; name=\"file\"; filename=\"foo.txt\"";
string contentType = "Content-Type: text/plain";
string fullContents = "{0}\r\n{1}\r\n{2}\r\n\r\n{3}\r\n{4}--", boundary, contentDisp,contentType, Encoding.Default.GetString(contents), boundary;
req.ContentLength = fullContents.Length;
using (StreamWriter reqStream = new StreamWriter(req.GetRequestStream()))
{

reqStream.Write(fullContents);
reqStream.Flush();
reqStream.Close();
}
var httpResponse = (HttpWebResponse)req.GetResponse(); //403 Error

[Nic Brough -Adaptavist-]

You haven't told us what error you're getting.