Num Lock, Caps Lock & Scoll Lock

[Djibril]

Could someone tell me how to toggle ON and OFF the Num Lock, Caps Lock & Scroll Lock leds?

Where there is a WISH, there is a WILL.

[ric]

Catch them in your overriden function PreTranslateMessage() and what ever you wanna do with them. Something like this:

int CMyDialog::PreTranslateMessage(MSG *pMsg)
{
if(pMsg->message==WM_KEYDOWN)
if(pMsg->wParam==VK_NLOCK ||pMsg->message==VK_CLOCK||pMsg->message==VK_SLOCK)
{
// do your stuff here like
return 0;
// or whatever you need
}

return CDialog::PretranslateMessage(pMsg);
}

[Smriti]

Hi,

You could refer to the KB article number Q127190 in the MSDN. This article tells you exactly how you can acieve this. He asks you to use the keybd_event() to do this. A sample code for toggling the num lock is also given. The sample is as follows:

#include <windows.h>

void SetNumLock( BOOL bState )

{
BYTE keyState[256];

GetKeyboardState((LPBYTE)&keyState);
if( (bState && !(keyState[VK_NUMLOCK] & 1)) ||
(!bState && (keyState[VK_NUMLOCK] & 1)) )
{
// Simulate a key press
keybd_event( VK_NUMLOCK,
0x45,
KEYEVENTF_EXTENDEDKEY | 0,
0 );

// Simulate a key release
keybd_event( VK_NUMLOCK,
0x45,
KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP,
0);
}
}

void main()

{
SetNumLock( TRUE );

}

VK_NUMLOCK is used for num lock. The same code can be modified with VK_CAPITAL & VK_SCROLL for caps lock & scroll lock respectively.

Hope this helps.

Regards,
Smriti Venkatesh