Bu% 2B ile + yerine, iş gibi görünüyor ...
private string HTTPPost(string URL, Dictionary<string, string> FormData)
{
UTF8Encoding UTF8encoding = new UTF8Encoding();
string postData = "";
foreach (KeyValuePair<String, String> entry in FormData)
{
postData += entry.Key + "=" + entry.Value + "&";
}
postData = postData.Remove(postData.Length - 1);
//urlencode replace (+) with (%2B) so it will not be changed to space ( )
postData = postData.Replace("+", "%2B");
byte[] data = UTF8encoding.GetBytes(postData);
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(URL);
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = data.Length;
Stream strm = request.GetRequestStream();
// Send the data.
strm.Write(data, 0, data.Length);
strm.Close();
WebResponse rsp = null;
// Send the data to the webserver
rsp = request.GetResponse();
StreamReader rspStream = new StreamReader(rsp.GetResponseStream());
string response = rspStream.ReadToEnd();
return response;
}