Turn off NumLock (Views: 28)
Problem/Question/Abstract: Using Delphi 5, I'm trying to setup a routine that would automatically turn off the NUMLOCK key when loaded. Assume that I am writing a standalone utility that could be loaded in the startup folder to do this function. Answer: Solve 1: procedure SwitchToggleKey(Key: byte; State: boolean); var ks: TKeyboardState; ScanCode: integer; begin if not key in [VK_CAPITAL, VK_NUMLOCK, VK_SCROLL, VK_INSERT] then exit; if (key = VK_NUMLOCK) and (Win32Platform = VER_PLATFORM_WIN32_WINDOWS) then begin GetKeyboardState(ks); {for Win95/98} if state then ks[key] := ks[key] or 1 else ks[key] := ks[key] and 254; SetKeyboardState(ks); end else if odd(GetKeyState(key)) <> state then begin ScanCode := MapVirtualKey(key, 0); keybd_event(key, ScanCode, {KEYEVENTF_EXTENDEDKEY} 0, 0); {Simulate a key release} keybd_event(key, ScanCode, {KEYEVENTF_EXTENDEDKEY or } KEYEVENTF_KEYUP, 0); end; end; Note that not all controls "honor" the INSERT key, and others will only respond to the INSERT key while they have focus. I'm surprised that the Extended Key "attribute" works for the non-extended keys. Strangely enough, it works as well without KEYEVENTF_EXTENDEDKEY. Solve 2: procedure SimulateKeystroke(Key: byte; extra: DWORD); begin keybd_event(Key, extra, 0, 0); keybd_event(Key, extra, KEYEVENTF_KEYUP, 0); end; function IsKeyToggled(key: byte): boolean; var state: word; begin state := windows.GetKeyState(key); result := (state mod 128) = 1; end; function CapsLockStatus: boolean; begin result := IsKeyToggled(VK_CAPITAL); end; function NumLockStatus: boolean; begin result := IsKeyToggled(VK_NUMLOCK); end; procedure ToggleCapsLock; begin SimulateKeystroke(VK_CAPITAL, 0); end; procedure ToggleNumLock; begin SimulateKeystroke(VK_NUMLOCK, 0); end; procedure TForm1.btnOnClick(Sender: TObject); begin if not NumLockStatus then ToggleNumLock; end; procedure TForm1.btnOffClick(Sender: TObject); begin if NumLockStatus then ToggleNumLock; end; Solve 3: I want to determine the state of the Num lock key on the keyboard and set it to on when my application begins or opens a specific form. Note that the keyboard LED may not reflect the keys state correctly on all Windows platforms if you set it this way in code. procedure SetLockKey(vcode: Integer; down: Boolean); begin if Odd(GetAsyncKeyState(vcode)) <> down then begin keybd_event(vcode, MapVirtualkey(vcode, 0), KEYEVENTF_EXTENDEDKEY, 0); keybd_event(vcode, MapVirtualkey(vcode, 0), KEYEVENTF_EXTENDEDKEY or KEYEVENTF_KEYUP, 0); end; end; SetLockKey(VK_NUMLOCK, True); {num lock down} |