Title: How to turn on/off Caps/Num/Scroll Lock
type
TKeyType = (ktCapsLock, ktNumLock, ktScrollLock);
procedure SetLedState(KeyCode: TKeyType; bOn: Boolean);
var
KBState: TKeyboardState;
Code: Byte;
begin
case KeyCode of
ktScrollLock: Code := VK_SCROLL;
ktCapsLock: Code := VK_CAPITAL;
ktNumLock: Code := VK_NUMLOCK;
end;
GetKeyboardState(KBState);
if (Win32Platform = VER_PLATFORM_WIN32_NT) then
begin
if Boolean(KBState[Code]) bOn then
begin
keybd_event(Code,
MapVirtualKey(Code, 0),
KEYEVENTF_EXTENDEDKEY,
0);
keybd_event(Code,
MapVirtualKey(Code, 0),
KEYEVENTF_EXTENDEDKEY or KEYEVENTF_KEYUP,
0);
end;
end
else
begin
KBState[Code] := Ord(bOn);
SetKeyboardState(KBState);
end;
end;
Usage Examples:
procedure TForm1.Button1Click(Sender: TObject);
begin
SetLedState(ktCapsLock, True); // CapsLock on
SetLedState(ktNumLock, True); // NumLock on
SetLedState(ktScrollLock, True); // ScrollLock on
end;