I finally got it with the following code …
var boundary = "------------------------" + DateTime.Now.Ticks;
var newLine = Environment.NewLine;
var propFormat = "--" + boundary + newLine +
"Content-Disposition: form-data; name=\"{0}\"" + newLine + newLine +
"{1}" + newLine;
var fileHeaderFormat = "--" + boundary + newLine +
"Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"" + newLine;
var req = (HttpWebRequest)HttpWebRequest.Create("http://jm/php/upload.php");
req.Method = WebRequestMethods.Http.Post;
req.ContentType = "multipart/form-data; boundary=" + boundary;
using (var reqStream = req.GetRequestStream()) {
var reqWriter = new StreamWriter(reqStream);
var tmp = string.Format(propFormat, "str1", "hello world");
reqWriter.Write(tmp);
tmp = string.Format(propFormat, "str2", "hello world 2");
reqWriter.Write(tmp);
reqWriter.Write("--" + boundary + "--");
reqWriter.Flush();
}
var res = req.GetResponse();
using (var resStream = res.GetResponseStream()) {
var reader = new StreamReader(resStream);
txt1.Text = reader.ReadToEnd();
}
Notice boundaries have to begin with --
{boundary declared in ContentType} and ending boundary must begin & end with --
. in my case, I originally used
var propFormat = boundary + newLine +
"Content-Disposition: form-data; name=\"{0}\"" + newLine + newLine +
"{1}" + newLine;
replace it with
var propFormat = "--" + boundary + newLine +
"Content-Disposition: form-data; name=\"{0}\"" + newLine + newLine +
"{1}" + newLine;
and everything works