Geek asks and answers

WebBrowserControl: UnauthorizedAccessException when accessing the Frame property

I encoded a very small website in C # using the default WebBrowser control. In fact, almost everything works the way it should work, but I seem to have problems with the last step of my automation.

The website was created using several frames. This is not very important, as I just access these frames and their elements with

webBrowser1.Document.Window.Frames[0].Document.GetElementById("element").InvokeMember("click");

However, it does not work when the IFRAME source is hosted in a different domain than the actual website. When I searched the Internet for an answer to my problem, I stumbled upon an MSDN article that mentioned this particular problem and they referred to security measures against cross-site scripting that might be causing this error.

I could not find a way to disable this feature, so I switched and decided to recode everything to work with geckofx-12 instead of the standard (IE-based) web browser, but I ran into similar problems ..

My question is: Is there a way around this annoying behavior? I don’t care about security issues or whether geckofx or the default web browser control is used, I would just like to programmatically access the elements of the site that is hosted in another domain, without using the UnauthorizedAccessException.

I would like advice from a guru.

+3
source share
3 answers

I have not tried this, but changing the document domain seems to work.

geckofx 12, , nsIDOMHTMLDocument.SetDomainAttribute( GeckoDocument.Domain setter, )

IE. , .

+1

. . :

 public class CrossFrameIE
{
    // Returns null in case of failure.
    public static IHTMLDocument2 GetDocumentFromWindow(IHTMLWindow2 htmlWindow)
    {
        if (htmlWindow == null)
        {
            return null;
        }

        // First try the usual way to get the document.
        try
        {
            IHTMLDocument2 doc = htmlWindow.document;                

            return doc;
        }
        catch (COMException comEx)
        {
            // I think COMException won't be ever fired but just to be sure ...
            if (comEx.ErrorCode != E_ACCESSDENIED)
            {
                return null;
            }
        }
        catch (System.UnauthorizedAccessException)
        {
        }
        catch
        {
            // Any other error.
            return null;
        }

        // At this point the error was E_ACCESSDENIED because the frame contains a document from another domain.
        // IE tries to prevent a cross frame scripting security issue.
        try
        {
            // Convert IHTMLWindow2 to IWebBrowser2 using IServiceProvider.
            IServiceProvider sp = (IServiceProvider)htmlWindow;

            // Use IServiceProvider.QueryService to get IWebBrowser2 object.
            Object brws = null;
            sp.QueryService(ref IID_IWebBrowserApp, ref IID_IWebBrowser2, out brws);

            // Get the document from IWebBrowser2.
            IWebBrowser2 browser = (IWebBrowser2)(brws);

            return (IHTMLDocument2)browser.Document;
        }
        catch
        {
        }

        return null;
    }

    private const int E_ACCESSDENIED = unchecked((int)0x80070005L);
    private static Guid IID_IWebBrowserApp = new Guid("0002DF05-0000-0000-C000-000000000046");
    private static Guid IID_IWebBrowser2 = new Guid("D30C1661-CDAF-11D0-8A3E-00C04FC9E26E");
}

// This is the COM IServiceProvider interface, not System.IServiceProvider .Net interface!
[ComImport(), ComVisible(true), Guid("6D5140C1-7436-11CE-8034-00AA006009FA"),
InterfaceTypeAttribute(ComInterfaceType.InterfaceIsIUnknown)]
public interface IServiceProvider
{
    [return: MarshalAs(UnmanagedType.I4)]
    [PreserveSig]
    int QueryService(ref Guid guidService, ref Guid riid, [MarshalAs(UnmanagedType.Interface)] out object ppvObject);
}
+6

, , , mshtml:

using mshtml;
using SHDocVw;
using System;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Windows.Forms;

namespace TradeAutomation
{
    public static class CrossFrameIE
    {
        private static FieldInfo ShimManager = typeof(HtmlWindow).GetField("shimManager", BindingFlags.NonPublic | BindingFlags.Instance);
        private static ConstructorInfo HtmlDocumentCtor = typeof(HtmlDocument).GetConstructors(BindingFlags.NonPublic | BindingFlags.Instance)[0];

        public static HtmlDocument GetDocument(this HtmlWindow window)
        {
            var rawDocument = (window.DomWindow as IHTMLWindow2).GetDocumentFromWindow();

            var shimManager = ShimManager.GetValue(window);

            var htmlDocument = HtmlDocumentCtor
                .Invoke(new[] { shimManager, rawDocument }) as HtmlDocument;

            return htmlDocument;
        }


        // Returns null in case of failure.
        public static IHTMLDocument2 GetDocumentFromWindow(this IHTMLWindow2 htmlWindow)
        {
            if (htmlWindow == null)
            {
                return null;
            }

            // First try the usual way to get the document.
            try
            {
                IHTMLDocument2 doc = htmlWindow.document;

                return doc;
            }
            catch (COMException comEx)
            {
                // I think COMException won't be ever fired but just to be sure ...
                if (comEx.ErrorCode != E_ACCESSDENIED)
                {
                    return null;
                }
            }
            catch (System.UnauthorizedAccessException)
            {
            }
            catch
            {
                // Any other error.
                return null;
            }

            // At this point the error was E_ACCESSDENIED because the frame contains a document from another domain.
            // IE tries to prevent a cross frame scripting security issue.
            try
            {
                // Convert IHTMLWindow2 to IWebBrowser2 using IServiceProvider.
                IServiceProvider sp = (IServiceProvider)htmlWindow;

                // Use IServiceProvider.QueryService to get IWebBrowser2 object.
                Object brws = null;
                sp.QueryService(ref IID_IWebBrowserApp, ref IID_IWebBrowser2, out brws);

                // Get the document from IWebBrowser2.
                IWebBrowser2 browser = (IWebBrowser2)(brws);

                return (IHTMLDocument2)browser.Document;
            }
            catch
            {
            }

            return null;
        }

        private const int E_ACCESSDENIED = unchecked((int)0x80070005L);
        private static Guid IID_IWebBrowserApp = new Guid("0002DF05-0000-0000-C000-000000000046");
        private static Guid IID_IWebBrowser2 = new Guid("D30C1661-CDAF-11D0-8A3E-00C04FC9E26E");
    }

    // This is the COM IServiceProvider interface, not System.IServiceProvider .Net interface!
    [ComImport(), ComVisible(true), Guid("6D5140C1-7436-11CE-8034-00AA006009FA"),
    InterfaceTypeAttribute(ComInterfaceType.InterfaceIsIUnknown)]
    public interface IServiceProvider
    {
        [return: MarshalAs(UnmanagedType.I4)]
        [PreserveSig]
        int QueryService(ref Guid guidService, ref Guid riid, [MarshalAs(UnmanagedType.Interface)] out object ppvObject);
    }
}

:

webBrowser1.Document.Window.Frames["main"].GetDocument();

, SHDocVw. : 'SHDocVw' # Visual # 2010 Express

+1

More articles:


All Articles