CODEWITHSUNDEEP
vb.netauthentication
Zelda
Zelda

Reputation: 2124

Operating on a web page using the Document Object

I have a VB.Net app that needs to print a bunch of pages from a secure intranet site; the app was made and was working for a non-secure site but now the app needs to login before accessing the web pages necessary to print.

I get the error "Object Reference not set to an instance of an object" when I use my new Sub which follows:

Private Sub SiteLogin()
    WebBrowser1.Navigate("http://url/login/")

    WebBrowser1.Document.GetElementById("user").SetAttribute("value", "username")
    WebBrowser1.Document.GetElementById("password").SetAttribute("value", "mypassword")

    WebBrowser1.Document.GetElementById("submit").InvokeMember("click")
End Sub

I got the code from this VB tutorial, but I seem to be missing something in how I'm referencing the WebBrowser.Document object. I've never used VB.Net before so I don't know much about this problem, I have the following sub which DOES work from the original program however:

Private Sub WebPrint()
    WebBrowser1.Navigate(strUrl)
    WebDocLoaded = False
    'lblMessage.Text = "Waiting for report page to load"
    Do Until WebDocLoaded
        System.Windows.Forms.Application.DoEvents()
    Loop
End Sub

This Sub prints the given page in IE, so I figured I could use the same WebBrowser1 object for the login Sub, as I don't know how to or whether I should declare a separate object for the SiteLogin Sub. Both of these functions are called after the WebBrowser1 object is defined however.

I just need to be able to submit a simple login form to a set URL, and this info needs to all be hardcoded (there's no option to set the location or login info nor should there be). If there's another way to log into this site via VB.Net or if I need to give more information let me know.

Upvotes: 1

Views: 928

Answers (1)

Alex K.
Alex K.

Reputation: 175896

.Navigate returns before the page load is complete so the DOM is not ready & .Document is not accessible.

See; How to wait until WebBrowser is completely loaded in VB.NET?

Upvotes: 1

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