Notes

private static HttpWebResponse PostForm(string postUrl, string userAgent, string contentType, byte[] formData)
{
HttpWebRequest request = WebRequest.Create(postUrl) as HttpWebRequest;


if (request == null)
{
throw new NullReferenceException("request is not a http request");
}
var uri = new Uri(postUrl);
// Set up the request properties.
request.ContentType = contentType;
request.Method = "POST";
request.UserAgent = userAgent;
WebHeaderCollection myWebHeaderCollection = request.Headers;
myWebHeaderCollection.Add("Accept-Encoding", "gzip, deflate");
myWebHeaderCollection.Add("Accept-Language", "tr-TR,tr;q=0.9,en-US;q=0.8,en;q=0.7");
myWebHeaderCollection.Add("Cache-Control", "max-age=0");
myWebHeaderCollection.Add("Save-Data", "on");
myWebHeaderCollection.Add("Upgrade-Insecure-Requests", "1");
myWebHeaderCollection.Add("Origin", "null");
request.CookieContainer = new CookieContainer();
cookie = GetCookie()[1].ToString();
string cookiname = cookie.Split(':')[0].ToString().Replace("Cookie['", "").Replace("']", "");
string cookievalue = "eyJpdiI6Ikc5YWk3Y1Vmd1wvTEhIekVPZXpKUUtBPT0iLCJ2YWx1ZSI6InVDY3BBZnZ5a2IwWkl1ZE9xU3grTnN4UW5Ha0MxdVlXOHFId25PR0ZHbVpoYkJLWFh1Ujd2MzRJZXBkYjAzaTMwOXRaT01GVXV3ZVpNbVwvdXBrTUF1Zz09IiwibWFjIjoiZTgzNTA1ZGVjMTJmN2MyODRiYmFkZjNjNWFlNzFhNTI3ODVlZDkwY2FmNmRiMTdkZmU4OGQ2NWY3NmRmNTQ4YSJ9";
request.CookieContainer.Add(new Cookie("_ga", "GA1.2.1707423240.1535509126", "/", uri.Host));
request.CookieContainer.Add(new Cookie("_gid", "GA1.2.55424933.1535509126", "/", uri.Host));
request.CookieContainer.Add(new Cookie(cookiname, cookievalue,"/",uri.Host));//cookie.Split(':')[1].ToString().Replace(" ", "").Replace("%3D %3D", "%3D"), "/", uri.Host));
request.CookieContainer.Add(new Cookie("XSRF-TOKEN", "eyJpdiI6IlBhQmFoQmt4ODk5VUkrY3YwT3pxM0E9PSIsInZhbHVlIjoiemlJNTJHbXZubis3OUJrRFRGcmxCRDlvY2VzazlBbTZHa0VZT21Lb25XVmVTck5kWmRrOHFaQ2NMN0RLYlRTbGJGZDZRdW5peFhFYlhQQ0lYdVhRU0E9PSIsIm1hYyI6ImNiZDA4MzE0ZGFkYzA3YmRlZmFkYWU4YTJlZTg1YzQyYTQyMjFkNjNkMzAzNDk4ODUyMjhkNjkzN2RmZWJiZmUifQ", "/", uri.Host));
request.CookieContainer.Add(new Cookie("_gat", "1", "/", uri.Host));
request.ContentLength = formData.Length;
request.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8";
request.Expect = "";
request.KeepAlive = true;
request.KeepAlive = true;
request.AllowAutoRedirect = false;
// You could add authentication here as well if needed:
request.PreAuthenticate = true;
// request.AuthenticationLevel = System.Net.Security.AuthenticationLevel.MutualAuthRequested;
// request.Headers.Add("Authorization", "Basic " + Convert.ToBase64String(System.Text.Encoding.Default.GetBytes("username" + ":" + "password")));

// Send the form data to the request.
using (Stream requestStream = request.GetRequestStream())
{
requestStream.Write(formData, 0, formData.Length);
requestStream.Close();
}
HttpWebResponse response = request.GetResponse() as HttpWebResponse;
if (response.StatusCode == HttpStatusCode.Redirect || response.StatusCode == HttpStatusCode.MovedPermanently)
{
MessageBox.Show("Başarısız");
}

return response;
}