keyboard hooks on a BHO

[Hema]

hi all,
i have implemented a keyboard hook which is active only when IE is
open. Its a BHO. I am adding the code below:
using System;
using System.Runtime. InteropServices ;
using System.Windows. Forms;
using System.Web.Serv ices;
using Microsoft.Win32 ;
using SHDocVw;

namespace KeyboardHooks_B HO
{

/// <summary>
/// Summary description for Class1.
/// </summary>
///
[ComVisible(true )]
[Guid("20C718C8-0D8C-42dc-B0CD-C7C53A23F116")]
public class BHO : IObjectWithSite
{
#region Member Variables
protected SHDocVw.IWebBro wser2 m_pIWebBrowser2 ; // the browser class
object
protected SHDocVw.DWebBro wserEvents2_Eve nt m_pDWebBrowserE vents2; //
browser events
// private ComImports KeyHook= new ComImports();

#endregion

#region Hook Variables

public struct KeyboardHookStr uct
{
public long vkCode;
public long scanCode;
public int flags;
public long time;
public long dwExtraInfo;

};
private const int HC_ACTION = 0;
private const int LLKHF_EXTENDED = 0x01;
private const int LLKHF_ALTDOWN = 0x20;
private const long VK_T = 0x54;
private const long VK_P = 0x50;
private const long VK_S = 0x53;
private const int WH_KEYBOARD_LL= 13;

protected IntPtr KeyboardHandle = IntPtr.Zero;
private static int mHook;
#endregion
public BHO()
{

MessageBox.Show ("inside BHO's constructor");
}
#region COM interfaces
#region IObjectWithSite Members

public void SetSite(object newSite)
{
MessageBox.Show ("inside SetSite");
object site=newSite;
string explorer= null;

if (m_pIWebBrowser 2!=null)
Release();

if( site != null )
Marshal.Release ComObject( site );

site = newSite;

if( site != null )
{
MessageBox.Show ("inside if site!=null");
IServiceProvide r sp = site as IServiceProvide r;
m_pIWebBrowser2 = site as SHDocVw.IWebBro wser2;
Guid guid = ExplorerGUIDs.I ID_IWebBrowserA pp;
Guid riid = ExplorerGUIDs.I ID_IUnknown;

object wba;
sp.QueryService (ref guid,ref riid,out wba );

/*explorer = (WebBrowserClas s)Marshal.Creat eWrapperOfType(
wba as SHDocVw.IWebBro wser2,
typeof(WebBrows erClass));*/

explorer=m_pIWe bBrowser2.FullN ame.ToUpper();

if(explorer.End sWith("IEXPLORE .EXE"))
{
MessageBox.Show ("inside the IEXPLORE.EXE");
// KeyHook.Install ();
Install();
MessageBox.Show ("hooking");

}
}
else
{
if ( explorer != null )
{
IServiceProvide r sp = site as IServiceProvide r;
m_pIWebBrowser2 = site as SHDocVw.IWebBro wser2;
Guid guid = ExplorerGUIDs.I ID_IWebBrowserA pp;
Guid riid = ExplorerGUIDs.I ID_IUnknown;

object wba;
sp.QueryService (ref guid,ref riid,out wba );

explorer=m_pIWe bBrowser2.FullN ame.ToUpper();
//Marshal.Release ComObject( explorer );

//explorer is about to close, freeing resources
if(explorer.End sWith("IEXPLORE .EXE"))
{
//KeyHook.UnInsta ll();
UnInstall();
MessageBox.Show ("UnHookMe") ;
}

explorer = null;
}
MessageBox.Show ("end of setsite");
return;
}

}

public int GetSite(ref Guid guid, out IntPtr ppvSite)
{
// TODO: Add BHO.GetSite implementation
MessageBox.Show ("inside getsite");
ppvSite = new IntPtr ();
return 0;
}

#endregion

protected void Release()
{
if (m_pDWebBrowser Events2!=null)
{
Marshal.Release ComObject(m_pDW ebBrowserEvents 2);
m_pDWebBrowserE vents2=null;
}

if (m_pIWebBrowser 2 != null)
{
Marshal.Release ComObject(m_pIW ebBrowser2);
m_pIWebBrowser2 = null;
}
}

#endregion

#region Hook Functions

private delegate int KeyboardHookPro cDelegate(int nCode, int wParam,
int lParam);

public void Install()
{
MessageBox.Show ("inside Install");
mHook=SetWindow sHookEx(WH_KEYB OARD_LL,new
KeyboardHookPro cDelegate(Keybo ardHookProc),In tPtr.Zero,0);
if(mHook!=0)
{
MessageBox.Show ("unable to install");
}
else
MessageBox.Show ("Success in Installing!");
}
public static int KeyboardHookPro c(int nCode, int wParam, int lParam)

{
KeyboardHookStr uct HookStruct;
int ret = 0;
MessageBox.Show ("inside HookProc");

HookStruct = (KeyboardHookSt ruct) Marshal.PtrToSt ructure(new
IntPtr(lParam), typeof(Keyboard HookStruct));
long vkCode= HookStruct.vkCo de;
int flag = HookStruct.flag s;

if(nCode==HC_AC TION)
{
MessageBox.Show ("inside nCode==HC_ACTIO N");
//System.Windows. Forms.Keys KeyPressed = (Keys)wParam.To Int32();

// Insert + T OR Alt + T
if(vkCode == VK_T )
{
if(flag==LLKHF_ EXTENDED)
{
MessageBox.Show ("Play");
ret=1;
}
else if((flag & LLKHF_ALTDOWN)! =0)
{
MessageBox.Show ("Stop");
ret=1;
}
}
else if((vkCode == VK_P)&&((flag & LLKHF_EXTENDED) !=0))
{ // Insert + P
MessageBox.Show ("pause");
ret = 1 ;
}
else if((vkCode == VK_S) && ((flag & LLKHF_ALTDOWN)! =0))
{ // Alt + S
MessageBox.Show ("Save");
ret = 1 ;
}

/*/ CopyMemory(Hook Struct,lParam,s izeof(HookStruc t);
if(IsHooked(Hoo kStruct))
{
MyKeyboardProc= 1;
}*/

// MyKeyboardProc= 1;
}
if( ret == 0 )
{
ret = CallNextHookEx( mHook,nCode,wPa ram,lParam);
}
return ret;
}
public void UnInstall()
{
MessageBox.Show ("inside UnInstall");
if(mHook!=0)
{
MessageBox.Show ("inside mHook!=0 ");
UnhookWindowsHo okEx(KeyboardHa ndle);
}
}
#endregion

#region Hook Win32Imports

// Win32: SetWindowsHookE x()
[DllImport("user 32.dll")]
private static extern int SetWindowsHookE x(int code,
KeyboardHookPro cDelegate func,
IntPtr hInstance,
int threadID);

// Win32: UnhookWindowsHo okEx()
[DllImport("user 32.dll")]
protected static extern int UnhookWindowsHo okEx(IntPtr hhook);
// Win32: CallNextHookEx( )
[DllImport("user 32.dll")]
protected static extern int CallNextHookEx( int hhook,
int code, int wParam, int lParam);
#endregion
}
}
the questions are:
1.the BHO is working fine, however, though SetWindowsHookE x getting
executed successfully,.. none of my hooks are working...
2. I guess the virtual keys are having some kind of problem. I dont
know how to solve this.
3.also my hook procedure is not getting called. y?
hope u is clear.
waiting for a clarification
thanks and regards,
hema