Iframe Access denied error - Add-in Express for IE forum

ryan J

Posts: 5
Joined: 2011-08-03

When I try to walk through the DOM of the page in the Iframe where the src is different domain, I get mshtml.IHTMLFrameBase {System.UnauthorizedAccessException}. When I try using the VS debugger to step through the object tree, when I get to the iframe on this domain, all the values say "Access Denied" or something similar. Is there any way to access iFrame DOM which has src of different domain.

ryan J

Posts: 5
Joined: 2011-08-03

Can anybody please answer this for me.

ryan J

Posts: 5
Joined: 2011-08-03

When I try to walk through the DOM of the page in the Iframe where the src is different domain, I get mshtml.IHTMLFrameBase {System.UnauthorizedAccessException}. When I try using the VS debugger to step through the object tree, when I get to the iframe on this domain, all the values say "Access Denied" or something similar. Is there any way to access iFrame DOM which has src of different domain.

Vladimir Lvov

Posts: 10
Joined: 2010-09-16

This function will do the conversion without UnauthorizedAccessException.


public static HTMLDocument ConvertToDocument(IHTMLElement frame)
        {
            try
            {
                return (HTMLDocument)((Interop.SHDocVw.IWebBrowser2)((HTMLFrameElement)frame)).Document;
            }
            catch
            {
                return null;
            }
        }

ryan J

Posts: 5
Joined: 2011-08-03

Thanks a lot.
I tried your solution and getting following error.

Message: Unable to cast COM object of type 'mshtml.HTMLWindow2Class' to interface type 'mshtml.IHTMLFrameElement'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{3050F313-98B5-11CF-BB82-00AA00BDCE0B}' failed due to the following error: No such interface supported (Exception from HRESULT: 0x80004002 (E_NOINTERFACE)).

My Code in VB.NET:
Private Sub __doHighlight(ByVal searchTerm As String, highlightColor As String)
Dim document As mshtml.HTMLDocument = HTMLDocument
If hasFrames() Then
Dim k As Integer = 0
For k = 0 To document.frames.length - 1
Dim frHTMLDoc As HtmlDocument = ConvertToDocument(document.frames.item(k))
If Not frHTMLDoc.Body Is Nothing Then
Dim bodyElement As Object = frHTMLDoc.Body
__highlightText(bodyElement, searchTerm, highlightColor)
bodyElement = Nothing
End If
Next
Else
If Not document.body Is Nothing Then
Dim bodyElement As Object = document.body
__highlightText(bodyElement, searchTerm, highlightColor)
bodyElement = Nothing
End If
End If
End Sub

Public Function ConvertToDocument(frame As mshtml.IHTMLFrameElement) As HtmlDocument
Try
Return DirectCast(DirectCast(DirectCast(frame, mshtml.HTMLFrameElement), Interop.SHDocVw.IWebBrowser2).Document, HtmlDocument)
Catch
Return Nothing
End Try
End Function

Vladimir Lvov

Posts: 10
Joined: 2010-09-16

Select frames as html elements instead of using document.frames.


             string[] frameTags = new string[] { "FRAME", "IFRAME" };
            foreach (string frameTag in frameTags)
            {
                IHTMLElementCollection framesCollection = document.getElementsByTagName(frameTag);
                foreach (IHTMLElement frame in framesCollection)
                {
                    HTMLDocument childDoc = ConvertToDocument(frame);
                    // Put your logic here
                }
            }

ryan J

Posts: 5
Joined: 2011-08-03

Thanks a lot. Its working fine now.

Sergey Grischenko

Add-in Express team

Posts: 7233
Joined: 2004-07-05

Hi Vladimir,

Thank you for the help. I have just sent you an email. Please check your inbox.