Thread: HttpWebRequest Question

Dear all,

I am connecting to web interface of a device which has username and password to authenticate. I managed to authenticate and load source of HTML page which i need. I need it to extract some data out of it. My code is as follows:

Imports System.Net

Imports System.Text

Imports System.IO



Public Class Form1

    Dim logincookie As CookieContainer

    



    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click



        Try

            Dim postData As String = "login_username=blabla&login_password=blabla&submit=Log+On"

            'Dim tempcookies As New CookieContainer

            Dim encoding As New UTF8Encoding

            Dim byteData As Byte() = encoding.GetBytes(postData)

            Dim postreq As HttpWebRequest = HttpWebRequest.Create("http://interface_address/Forms/login1")

            Dim cr As New System.Net.NetworkCredential("username", "password", "domain")

            Dim pr As New System.Net.WebProxy("proxy_address", 8080)

            pr.Credentials = cr

            postreq.Proxy = pr

            postreq.Method = "POST"

            postreq.KeepAlive = True

            'postreq.CookieContainer = tempcookies

            postreq.UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 6.1; ru; rv:1.9.2.3) Gecko/20100401 Firefox/4.0 (.NET CLR 3.5.30729"

            postreq.ContentType = "application/x-www-form-urlencoded"

            postreq.Referer = "http://interface_address/thsens.htm"

            postreq.ContentLength = byteData.Length

            postreq.AllowAutoRedirect = True

            postreq.MaximumAutomaticRedirections = 1000

            'postreq.Timeout = 5000

            Dim postreqstream As Stream = postreq.GetRequestStream



            postreqstream.Write(byteData, 0, byteData.Length)



            Dim postresponse As HttpWebResponse

            postresponse = DirectCast(postreq.GetResponse, HttpWebResponse)



            Dim postreqreader As New StreamReader(postresponse.GetResponseStream())

            'tempcookies.Add(postresponse.Cookies)

            'logincookie = tempcookies

            Dim thepage As String = postreqreader.ReadToEnd





            Me.TextBox1.Text = thepage

            postreq = HttpWebRequest.Create("http://interface_address/logout.htm")

            postreq.Proxy = pr

            postreq.GetResponse()

            postresponse.Close()

            'postreqstream.Close()

            postreqreader.Close()

        Catch ex As Exception

            MessageBox.Show(ex.Message)

        End Try        

    End Sub

End Class

I want to refresh textbox every, lets say, 15 seconds. When i press button it refreshes textbox, second time too, but third time it freezes on

Dim postreqstream As Stream = postreq.GetRequestStream

I wonder why, and how to solve this issue.

Thanks in advance

Originally Posted by line 38

Dim postreqstream As Stream = postreq.GetRequestStream

Close it when you're done with it.

Originally Posted by line 47

postreq.GetResponse()

Close response when you're done with it.

Originally Posted by JohnH

Close it when you're done with it.

Close response when you're done with it.

Sorry about late response.

I did it like you said and it works. Thanks.

I am logged in and redirected to /home.htm

how to load /thsens.htm since I am logged in, because I want to extract data from that page?

Regards

Request it, use same CookieContainer object as for login.