Include issues

[Garth J Lancaster]

ummmm, no you need to run your keyblocker program from the 'base program' using maybe createprocess(), or, refactor the guts of the keyblocker into a dll or class, then include that in the base and execute the code 'g'

[gamefreak2291]

yeah, i continued doing even more research after this and i found the CreateProcess() api. I tried to include it in on my program and it didnt work either, considering i've never used it before or anything. So i attempted to open the program via system("filepath"); and it compiled just fine but still didnt work. im open to any suggestions to get it going

[Stuart Dootson]

What you probably want is a thread level keyboard hook that looks at incoming keyboard events and blocks/unblocks input as desired (i.e. does what your keyblocker.cpp does). See this introduction to Windows hooks[^].

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

[gamefreak2291]

ive already attempted to write a keyboard hook and a .dll file, i didnt get either to work though. Let the record show that i am not a programming student yet, im simply trying to get very familiar before i start next year. so im going off of the little bit ive read in my books and internet. so im sorry if i seem very incompetent, but im sure ill get it eventually. so anyhow, i think the issue with my system("filepath"): command not working is because i had to switch from my xp machine to my vista machine and some changes between the two may be the reason why its not working so ill test he system part on my other pc tomorrow

[Stuart Dootson]

The thing is that BlockInput only blocks the input queue of the thread it's executed in - at least that's what the documentation[^] says, so your separate process implementation can't work, as it can only block its own input. Also - a keyboard hook doesn't need a DLL if it's just for your current thread. The following code adds a hook to the calling thread that blocks input if the 'A' key is pressed. To activate it, you just need to call the StartBlockingFilter function.

HHOOK myHook = 0;

LRESULT CALLBACK KeyboardFilter(int code, WPARAM wParam, LPARAM lParam)
{
if (wParam == 'a' || wParam == 'A')
BlockInput(TRUE);
return CallNextHookEx(myHook, code, wParam, lParam);
}

void StartBlockingFilter()
{
myHook = ::SetWindowsHookEx(WH_KEYBOARD, &KeyboardFilter, 0, GetCurrentThreadId());
}

void FinishBlockingFilter()
{
BlockInput(FALSE);
::UnhookWindowsHookEx(myHook);
}

You could put this code in a .cpp file, #include it and call StartBlockingFilter from where it was included.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

[gamefreak2291]

Uh, so I attempted to add that code into a .ccp file, but it failed to compile properly afterwards. I don't know whether there were things I needed to change or add to it because I've never gone over keyboard hooks before. Terribly sorry for all the issues..

[Stuart Dootson]

You'd need to #include <Windows.h> before that code.

gamefreak2291 wrote:

Uh, so I attempted to add that code into a .ccp file, but it failed to compile properly afterwards

What errors did you get?

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

[gamefreak2291]

#include #include #include using namespace std;

int main(void)
{

HHOOK myHook = 0;

LRESULT CALLBACK KeyboardFilter(int code, WPARAM wParam, LPARAM lParam)
{
if (wParam == 'a' || wParam == 'A')
BlockInput(TRUE);
return CallNextHookEx(myHook, code, wParam, lParam);
}

void StartBlockingFilter()
{
myHook = ::SetWindowsHookEx(WH_KEYBOARD, &KeyboardFilter, 0, GetCurrentThreadId());
}

void FinishBlockingFilter()
{
BlockInput(FALSE);
::UnhookWindowsHookEx(myHook);
}
}

return 0;
}

There's the code I used, and the errors I got are as follows:

H:\Programs\Worthwhile Programs\hidden\hooker.cpp In function `int main()':
12 H:\Programs\Worthwhile Programs\hidden\hooker.cpp a function-definition is not allowed here before '{' token
18 H:\Programs\Worthwhile Programs\hidden\hooker.cpp expected primary-expression before "void"
18 H:\Programs\Worthwhile Programs\hidden\hooker.cpp expected `;' before "void"
23 H:\Programs\Worthwhile Programs\hidden\hooker.cpp expected primary-expression before "void"
23 H:\Programs\Worthwhile Programs\hidden\hooker.cpp expected `;' before "void"
23 H:\Programs\Worthwhile Programs\hidden\hooker.cpp At global scope:
30 H:\Programs\Worthwhile Programs\hidden\hooker.cpp expected unqualified-id before "return"
30 H:\Programs\Worthwhile Programs\hidden\hooker.cpp expected `,' or `;' before "return"
31 H:\Programs\Worthwhile Programs\hidden\hooker.cpp expected declaration before '}' token

[Stuart Dootson]

OK....you needed to put the code in your main.cpp, NOT in the main function - you aren't allowed to define nested functions in C++.

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

[gamefreak2291]

Sigh, alright I added the code into my main file and I got it to compile without errors after one simple tweak. I then added in LONG StartBlockingFilter into a spot of my main() function and it is still compiling properly, however its not blocking input when I press a or A. I'm thinking its going to be a major issue.. I'm thinking that the keyboard hook is not going to work with MessageBoxes, which my entire code revolves around. I don't know if the Message Boxes are the issue are not, i hope not.

[Stuart Dootson]

gamefreak2291 wrote:

I'm thinking that the keyboard hook is not going to work with MessageBoxes

The keyboard hook works OK - the BlockInput, however, doesn't. You can, however, simulate BlockInput by using keyboard and mouse hooks to stop messages getting through - this code stops mouse and keyboard messages being sent to the message box:

HHOOK myKeyboardHook = 0;
HHOOK myMouseHook = 0;
bool blocking = false;

LRESULT CALLBACK KeyboardFilter(int nCode, WPARAM wParam, LPARAM lParam)
{
if (nCode < 0) return CallNextHookEx(myKeyboardHook, nCode, wParam, lParam);
if (wParam == 'a' || wParam == 'A')
blocking = true;
else if (wParam == 'b' || wParam == 'B')
blocking = false;
if (blocking) return 1;
return CallNextHookEx(myKeyboardHook, nCode, wParam, lParam);
}

LRESULT CALLBACK MouseFilter(int nCode, WPARAM wParam, LPARAM lParam)
{
if (nCode < 0 || !blocking) return CallNextHookEx(myMouseHook, nCode, wParam, lParam);
return 1;
}
void StartBlockingFilter()
{
myKeyboardHook = ::SetWindowsHookEx(WH_KEYBOARD, &KeyboardFilter, 0, GetCurrentThreadId());
myMouseHook = ::SetWindowsHookEx(WH_MOUSE, &MouseFilter, 0, GetCurrentThreadId());
}

void FinishBlockingFilter()
{
::UnhookWindowsHookEx(myKeyboardHook);
::UnhookWindowsHookEx(myMouseHook);
}

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

[gamefreak2291]

Alright, I threw in the new bit of code and it also compiled correctly. However I still can't get it to block input when I press a or A. I'm not sure if I'm calling it correctly, I'm trying to call it as follows:

{ LONG StartBlockingFilter;
MessageBox(NULL, "Welcome to my program", "Welcome", MB_OK);
MessageBox(NULL, "Just run through all the messages\n" "and you'll be done", "Instructions", MB_OK);
MessageBox(NULL, "Oh, and a word of warning.. I wouldn't\n" "suggest using Ctrl+Alt+Del, Alt+Tab\n"
"the Windows keys, the Escape keys\n" "or your mouse..", "Warning", MB_OK);}

Is that the correct way to call it into use?

[Stuart Dootson]

Noooo - you need to call StartBlockingFilter, not declare a variable of that name:

{ StartBlockingFilter();
MessageBox(NULL, "Welcome to my program", "Welcome", MB_OK);
MessageBox(NULL, "Just run through all the messages\n" "and you'll be done", "Instructions", MB_OK);
MessageBox(NULL, "Oh, and a word of warning.. I wouldn't\n" "suggest using Ctrl+Alt+Del, Alt+Tab\n"
"the Windows keys, the Escape keys\n" "or your mouse..", "Warning", MB_OK);}

Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p

[gamefreak2291]

Alright I switched it to StartBlockingFilter(); but it still did not work but it still is not blocking the input when I press a or A. I also sent you and e-mail explaining more. Respond if you want