WebBrowser Url to string not work

Question

When the code reaches MessageBox.Show() it throws an exception Object reference not set to an instance of an object.

Here is my code:

WebBrowser webb = new WebBrowser();    
webb.Navigate("https://www.facebook.com/logout.php?next=http://facebook.com&access_token=" + Settings.Default["token"].ToString());

MessageBox.Show(webb.Url.AbsoluteUri.ToString());

Do you see a reason why this might be the case ?

Could you tell please which exactly line of code throws this exception? — alex.b, May 21 '13 at 16:02
Set a breakpoint, and see where you're trying to access an object or a property that is null. — Arian Motamedi, May 21 '13 at 16:02
line error messagebox MessageBox.Show(webb.Url.AbsoluteUri.ToString()); — Federal09, May 21 '13 at 16:02
@Federal09, I've got guess `Url` property could be null while browser's navigation is not completed. — alex.b, May 21 '13 at 16:06
@Federal09, I'd suggest you might try subscribe to `OnNavigated` or `OnDocumentCompleted` event and access to the `Url` property in the handler. — alex.b, May 21 '13 at 16:08
http://stackoverflow.com/questions/4660142/what-is-a-nullreferenceexception-in-net — Alex Butenko, May 21 '13 at 18:16

score 1 · Accepted Answer · edited May 21 '13 at 16:22

This might work:

WebBrowser webb = new WebBrowser();

private void pictureBox3_Click(object sender, EventArgs e)
{        
    webb.Url = new Uri("https://www.facebook.com/logout.php?next=http://facebook.com&access_token=" + Settings.Default["token"].ToString());
    webb.DocumentCompleted += new System.Windows.Forms.WebBrowserDocumentCompletedEventHandler(this.webBrowser1_DocumentCompleted);        
}

private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
    MessageBox.Show(webb.Url.AbsoluteUri.ToString());
}

WebBrowser Url to string not work

1 Answers1