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Webbrowser control and threading

I am trying to use a webbrowser control to retrieve some information from a couple of websites. ( Login, send some data, click some button... etc)
I've created subs for every site i need to login to (yahoo, bla.. bla)
Then when a button is clicked i called the functions like so:

Private
 Sub
 submit_btn_Click(ByVal
 sender As
 System.Object, ByVal
 e As
 System.EventArgs) Handles
 submit_btn.Click

       call
 SubNameHere

      call
 SubName
    End
 Sub

Now what i need is a second button so I can pause or stop the current calls
I searched around and found threading to be perfect for what I need, but I can't get the browser to work.
I tried to change the button to:

Private Sub submit_btn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles submit_btn.Click

        Dim t As New Thread(AddressOf thr1)
        t.Start()
    End Sub

and thr1 as:

Private
 Sub
 thr1()
        Try

            Dim
 browser As
 New
 WebBrowser
            browser.ScriptErrorsSuppressed = True

            browser.Visible = True

            Timer2.Enabled = True

            results.Text = ""

            Call
 func1
            Call
 func2
        Catch
 ex As
 Exception
            MsgBox("Error: "
 & ex.Message)
        End
 Try

    End
 Sub

Sample of func1:

public sub func1()
browser.Navigate("some url")
browser.getelementbyid.... etc!
end sub

Any thoughts?

Proud tutorial creator for hackyourwindows.com :)

Gavro Saturday, November 28, 2009 4:11 PM

Note that WebBrowser is like most Windows controls and expects to run on a single thread. Since it downloads in the background, this normally is not a problem. Not sure why you need to introduce multiple threads given the built-in background processing automatic to the WebBrowser.

BinaryCoder Sunday, November 29, 2009 2:00 AM

Well.. actually i needed a way to control the process. You see, I have a sub created for every site i need to login and retrieve data. And that means like 40 subs. Now if my user wants to stop the process at any time, I really don't know how to do it.
Ideally what I need is a way to pause/stop the process at any time, and if possible to have a button for skipping current site. I thought the separate thread will do the job for the pause/stop part. Still no idea for the skip current website(sub)...
If someone can suggest a better approach... I'm open! Thanks!

Proud tutorial creator for hackyourwindows.com :)

Gavro Sunday, November 29, 2009 7:15 AM

Latest update: after searching for 10 hr i found something, i think, but didn't try it though.
It seems I need to create a thread, then in that thread to ad a sub that invokes the thread with the webbrowser control... something like that... I'm confused... :(

Proud tutorial creator for hackyourwindows.com :)

Gavro Sunday, November 29, 2009 10:38 AM

Let me step back and explain again:
I use Visual Basic.net to create a program that connects to several websites, logins, then post some data. I can't use the httpwebrequest, some java is required on those sites, so i use the webbrowser control.
Now I created a form, some fields for input data and a submit button. The coding part is like this:

Code:

sub website1(vars)

'login here

'post some data

'get some data back

'etc

end sub

So every site has its own sub.
Now the submit button calls all of these subs:

Code:

Private Sub submit_btn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles submit_btn.Click

call website1

call website2

End Sub

The problem is that I can't control what happens after submit button is clicked. I need to pause or stop the process at any time. If I exit the program while processing, I can see that even if the window disappear, the program is still running!
I tried to use a thread for this, but the subs only get called if I use begininvoke, or invoke on a starter thread... A real mess that I don't quite understand as a beginner.
Any thoughts are appreciated.

Proud tutorial creator for hackyourwindows.com :)

Gavro Sunday, November 29, 2009 9:52 PM

You can use google to search for other answers

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