asked on

Disabling [CRTL + ESC]

I have made a little client server program. The program is loaded as shell from system.ini.
I have made alittle dll to prevent users from pressing [CRTL + ESC] to start tasklist or an explorer. When I use this little dll it works fine as long as I not load the program as shell, but when I do I am not able to press on a main-menu or move scrollbars d:(
What is wrong and how can I solve this.

BTW I am using Delphi 4 Client / Server, and I want my program to work no matter if you are in win95 or win98 (no NT)
Thank in advance, Fantasia

Madshi

Can you please post the code of your little dll? Only thing that I can imagine is that there is something wrong with that.

If you don't use this dll, you can click at your mainmenu again, right?

Regards, Madshi.

heathprovost

How are you disabling [CRTL + ESC]? I mean what method are you using

fantasia123098

ASKER

4 Madshi (and heathprovost) this is the source code :
library ClientDll;

{$C FIXED PERMANENT PRELOAD}

uses
WinProcs,
SysUtils;
Const
hHookCBT : THandle = 0;

function CBTHookFunc( nCode : Integer;
wparam : WParam;
lparam : LParam): LRESULT stdCall;
begin
if nCode=HCBT_SYSCOMMAND then begin
MessageBeep(0);
Result:=1; { removes message }
end
else
{ call next hook in chain }
Result:=CallNextHookEx(hHookCBT, nCode, wParam, lParam);
end;

procedure InstallCBTHook; EXPORT;
var
hLib : THandle;
hProgMan : HWnd;
begin
hLib:=GetModuleHandle('ClientDll');
if (hHookCBT=0) then begin
hProgMan:=FindWindow('Progman', NIL);
hHookCBT:=SetWindowsHookEx(WH_CBT, @CBTHookFunc, hLib,
GetWindowThreadProcessId(hProgMan, nil));
end;
end;

procedure RemoveCBTHook; EXPORT;
begin
if (hHookCBT<>0) then begin
UnhookWindowsHookEx(hHookCBT);
hHookCBT:=0;
end;
end;

EXPORTS
InstallCBTHook,
RemoveCBTHook;

end.

in the Main form´s OnCreate event i typed

"InstallCBTHook" and I remove when the machine restarts.

If I call the procedure "RemoveCBTHook" it works ok again, also if I don´t use the DLL then the mainmenus and scrollbars are just fine. What is the problem, I think that I have made a mistake :)

Fantasia

ASKER CERTIFIED SOLUTION

Madshi

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fantasia123098

ASKER

Hi Madshi, Thank you for the good information, now I will try to fix this little Dll.
Is it ok if I post again if I can´t make it work?

Fantasia

Madshi

Yes, of course... :-)

fantasia123098

ASKER

4 Madshi.
Phew - I will never get this app to run :(
I can´t make it work, what am I doing wrong? Please Help

Madshi

Hi fantasia,

try to use this CBTHookFunc in your dll:

function CBTHookFunc(nCode: integer; wparam: wParam; lparam: lParam) : LRESULT; stdCall;
begin
if (nCode=HCBT_SYSCOMMAND) and
((wParam=SC_TASKLIST) or (wParam=SC_NEXTWINDOW) or (wParam=SC_PREVWINDOW)) then begin
MessageBeep(0);
result:=1; // removes message
end else // call next hook in chain
result:=CallNextHookEx(hHookCBT,nCode,wParam,lParam);
end;

If that doesn't work, please tell me WHAT does not work in detail. Then you'll probably have to wait two days. In the moment I've no free time at all. In 2 days I can test it for you...

Regards, Madshi.

fantasia123098

ASKER

Thank you Madshi, I will noe try to use it.
In the dll I made I did something like :
"case wParam of", but it did not work the right way.

Thans from Fantasia