HttpWebRequest C# uploading a file
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I had got the same problem and this following code answered perfectly at this problem :
//Identificate separator
string boundary = "---------------------------" + DateTime.Now.Ticks.ToString("x");
//Encoding
byte[] boundarybytes = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "\r\n");
//Creation and specification of the request
HttpWebRequest wr = (HttpWebRequest)WebRequest.Create(url); //sVal is id for the webService
wr.ContentType = "multipart/form-data; boundary=" + boundary;
wr.Method = "POST";
wr.KeepAlive = true;
wr.Credentials = System.Net.CredentialCache.DefaultCredentials;
string sAuthorization = "login:password";//AUTHENTIFICATION BEGIN
byte[] toEncodeAsBytes = System.Text.ASCIIEncoding.ASCII.GetBytes(sAuthorization);
string returnValue = System.Convert.ToBase64String(toEncodeAsBytes);
wr.Headers.Add("Authorization: Basic " + returnValue); //AUTHENTIFICATION END
Stream rs = wr.GetRequestStream();
string formdataTemplate = "Content-Disposition: form-data; name=\"{0}\"\r\n\r\n{1}"; //For the POST's format
//Writting of the file
rs.Write(boundarybytes, 0, boundarybytes.Length);
byte[] formitembytes = System.Text.Encoding.UTF8.GetBytes(Server.MapPath("questions.pdf"));
rs.Write(formitembytes, 0, formitembytes.Length);
rs.Write(boundarybytes, 0, boundarybytes.Length);
string headerTemplate = "Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\nContent-Type: {2}\r\n\r\n";
string header = string.Format(headerTemplate, "file", "questions.pdf", contentType);
byte[] headerbytes = System.Text.Encoding.UTF8.GetBytes(header);
rs.Write(headerbytes, 0, headerbytes.Length);
FileStream fileStream = new FileStream(Server.MapPath("questions.pdf"), FileMode.Open, FileAccess.Read);
byte[] buffer = new byte[4096];
int bytesRead = 0;
while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0)
{
rs.Write(buffer, 0, bytesRead);
}
fileStream.Close();
byte[] trailer = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "--\r\n");
rs.Write(trailer, 0, trailer.Length);
rs.Close();
rs = null;
WebResponse wresp = null;
try
{
//Get the response
wresp = wr.GetResponse();
Stream stream2 = wresp.GetResponseStream();
StreamReader reader2 = new StreamReader(stream2);
string responseData = reader2.ReadToEnd();
}
catch (Exception ex)
{
string s = ex.Message;
}
finally
{
if (wresp != null)
{
wresp.Close();
wresp = null;
}
wr = null;
}
Author by
user204588
Updated on June 12, 2020Comments
-
user204588 about 4 years
using C#, I'm trying to integrate my web store w/ an email marketing client. I want to upload a comma delimited file of subscribers once a night. They say to get this to work, it has to be a form posts: multipart/form-data, but I'm not using a form. I'm able to connect to their servers but I keep getting back a Data can't be blank. Can anyone help me to get this working?
public static string Create() { string authInfo = "username" + ":" + "password"; string root = AppDomain.CurrentDomain.BaseDirectory; string file = root + "Folder\\work.txt"; FileInfo fi = new FileInfo(file); int fileLength = (int)fi.Length; FileStream rdr = new FileStream(file, FileMode.Open); HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create(url); httpWebRequest.Method = "POST"; httpWebRequest.ContentType = "application/x-www-form-urlencoded"; httpWebRequest.Accept = "application/xml"; authInfo = Convert.ToBase64String(Encoding.Default.GetBytes(authInfo)); httpWebRequest.Headers["Authorization"] = "Basic " + authInfo; byte[] requestBytes = new byte[fileLength]; int bytesRead = 0; httpWebRequest.ContentLength = requestBytes.Length; using (Stream requestStream = httpWebRequest.GetRequestStream()) { while ((bytesRead = rdr.Read(requestBytes, 0, requestBytes.Length)) != 0) { requestStream.Write(requestBytes, 0, bytesRead); requestStream.Close(); } } //READ RESPONSE FROM STREAM string responseData; using (StreamReader responseStream = new StreamReader(httpWebRequest.GetResponse().GetResponseStream())) { responseData = responseStream.ReadToEnd(); responseStream.Close(); } return responseData; }