I don't know what is wrong since this code works amazing for me every time, but for an single website it give me an error called NullReferenceException was undhandled
at mainCookie.Add(postResponse.Cookies)
line.
Here is the code:
Dim mainCookie As CookieContainer
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim postData As String = "login=login&username=" & UserText.Text & "&password=" & PassText.Text & "&login=Login"
Dim bytes() As Byte = ASCIIEncoding.UTF8.GetBytes(postData)
Dim postReq As HttpWebRequest = WebRequest.Create("http://website.com/login.php")
postReq.Method = "POST"
postReq.KeepAlive = True
postReq.CookieContainer = mainCookie
postReq.ContentType = "application/x-www-form-urlencoded"
postReq.Referer = "http://website.com/"
postReq.UserAgent = "Mozilla/5.0 (Windows NT 10.0; rv:41.0) Gecko/20100101 Firefox/41.0"
postReq.ContentLength = bytes.Length
Dim postStream As Stream = postReq.GetRequestStream()
postStream.Write(bytes, 0, bytes.Length)
postStream.Close()
Dim postResponse As HttpWebResponse
postResponse = postReq.GetResponse()
mainCookie.Add(postResponse.Cookies)
Dim reader As New StreamReader(postResponse.GetResponseStream())
Dim strSource As String = reader.ReadToEnd
If strSource.Contains("Welcome") Then
MessageBox.Show("Login Successful")
TextBox1.Text = strSource
Else
MessageBox.Show("Login Failed")
TextBox1.Text = strSource
End If
End Sub