My Internet Explorer add-on does not work

Question

I have written sample IE add-on (based on samples found on internet). This addon makes log file and writes in it informations from OnDocumentComplete and OnBeforeNavigate2 events. Unfortunatelly this is not working. I successfully instaled this addon in IE and it is visible - but as I said, it is not working(informations are not written in log file).

And here is code of this addon:

using System;
using System.Collections.Generic;
using System.Text;
using SHDocVw;
using mshtml;
using System.IO;
using Microsoft.Win32;
using System.Runtime.InteropServices;
using System.Security.AccessControl;

namespace BHO_SampleApp
{

    [ComVisible(true),
    Guid("8a194578-81ea-4850-9911-13ba2d71efbd"),
    ClassInterface(ClassInterfaceType.None)
    ]
    public class BHO:IObjectWithSite
    {
        WebBrowser webBrowser;
        public void OnDocumentComplete(object pDisp, ref object URL)
        {
            using (StreamWriter sw = new StreamWriter(@"C:\log.txt"))
            {
                sw.WriteLine(String.Format("site: {0}, {1}", URL, DateTime.Now.ToString("dd-MM-yyyy HH:mm:ss")));
            }
        }

        public void OnBeforeNavigate2(object pDisp, ref object URL, ref object Flags, ref object TargetFrameName, ref object PostData, ref object Headers, ref bool Cancel)
        {
            using (StreamWriter sw = new StreamWriter(@"C:\log.txt"))
            {
                sw.WriteLine(String.Format("site: {0}, {1}", URL, DateTime.Now.ToString("dd-MM-yyyy HH:mm:ss")));
            }        
        }

        #region BHO Internal Functions
        public static string BHOKEYNAME = "Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Browser Helper Objects";

        [ComRegisterFunction]
        public static void RegisterBHO(Type type)
        {
            RegistryKey registryKey = Registry.LocalMachine.OpenSubKey(BHOKEYNAME, true);

            if (registryKey == null)
                registryKey = Registry.LocalMachine.CreateSubKey(BHOKEYNAME);

            string guid = type.GUID.ToString("B");
            RegistryKey ourKey = registryKey.OpenSubKey(guid);

            if (ourKey == null)
                ourKey = registryKey.CreateSubKey(guid);

            ourKey.SetValue("Alright", 1);
            registryKey.Close();
            ourKey.Close();
        }

        [ComUnregisterFunction]
        public static void UnregisterBHO(Type type)
        {
            RegistryKey registryKey = Registry.LocalMachine.OpenSubKey(BHOKEYNAME, true);
            string guid = type.GUID.ToString("B");

            if (registryKey != null)
                registryKey.DeleteSubKey(guid, false);
        }

        public int SetSite(object site)
        {
            if (site != null)
            {
                webBrowser = (WebBrowser)site;
                webBrowser.DocumentComplete += new DWebBrowserEvents2_DocumentCompleteEventHandler(this.OnDocumentComplete);
                webBrowser.BeforeNavigate2+=new DWebBrowserEvents2_BeforeNavigate2EventHandler(this.OnBeforeNavigate2);
            }
            else
            {
                webBrowser.DocumentComplete -= new DWebBrowserEvents2_DocumentCompleteEventHandler(this.OnDocumentComplete);
                webBrowser.BeforeNavigate2 -= new DWebBrowserEvents2_BeforeNavigate2EventHandler(this.OnBeforeNavigate2);
                webBrowser = null;
            }
            return 0;
        }

        public int GetSite(ref Guid guid, out IntPtr ppvSite)
        {
            IntPtr punk = Marshal.GetIUnknownForObject(webBrowser);
            int hr = Marshal.QueryInterface(punk, ref guid, out ppvSite);
            Marshal.Release(punk);

            return hr;
        }
        #endregion
    }

    [
    ComVisible(true),
    InterfaceType(ComInterfaceType.InterfaceIsIUnknown),
    Guid("FC4801A3-2BA9-11CF-A229-00AA003D7352")
    ]
    public interface IObjectWithSite
    {
        [PreserveSig]
        int SetSite([MarshalAs(UnmanagedType.IUnknown)]object site);
        [PreserveSig]
        int GetSite(ref Guid guid, out IntPtr ppvSite);
    }
}

what is wrong with this addon?

Answer 1

http://surecode.me/aknoblog/在这里您可以找到一个工作片段。

Answer 2

If your browser is in Protected Mode (default), your add-on does not have the right to write to c:\\log.txt. Try to disable he Protect Mode to check if it starts working.