procedure PostKeyExHWND(hWindow: HWnd; key: Word;
const shift: TShiftState;
specialkey: Boolean);
{************************************************************
* Procedure PostKeyEx
*
* Parameters:
* hWindow: target window to be send the keystroke
* key : virtual keycode of the key to send. For printable
* keys this is simply the ANSI code (Ord(character)).
* shift : state of the modifier keys. This is a set, so you
* can set several of these keys (shift, control, alt,
* mouse buttons) in tandem. The TShiftState type is
* declared in the Classes Unit.
* specialkey: normally this should be False. Set it to True to
* specify a key on the numeric keypad, for example.
* If this parameter is true, bit 24 of the lparam for
* the posted WM_KEY* messages will be set.
* Description:
* This procedure sets up Windows key state array to correctly
* reflect the requested pattern of modifier keys and then posts
* a WM_KEYDOWN/WM_KEYUP message pair to the target window. Then
* Application.ProcessMessages is called to process the messages
* before the keyboard state is restored.
* Error Conditions:
* May fail due to lack of memory for the two key state buffers.
* Will raise an exception in this case.
* NOTE:
* Setting the keyboard state will not work across applications
* running in different memory spaces on Win32 unless AttachThreadInput
* is used to connect to the target thread first.
*Created: 02/21/96 16:39:00 by P. Below
************************************************************}
type
TBuffers =
array [0..1]
of TKeyboardState;
var
pKeyBuffers: ^TBuffers;
lParam: LongInt;
begin
(* check if the target window exists *)
if IsWindow(hWindow)
then
begin
(* set local variables to default values *)
pKeyBuffers :=
nil;
lParam := MakeLong(0, MapVirtualKey(key, 0));
(* modify lparam if special key requested *)
if specialkey
then
lParam := lParam
or $1000000;
(* allocate space for the key state buffers *)
New(pKeyBuffers);
try
(* Fill buffer 1 with current state so we can later restore it.
Null out buffer 0 to get a "no key pressed" state. *)
GetKeyboardState(pKeyBuffers^[1]);
FillChar(pKeyBuffers^[0], SizeOf(TKeyboardState), 0);
(* set the requested modifier keys to "down" state in the buffer*)
if ssShift
in shift
then
pKeyBuffers^[0][VK_SHIFT] := $80;
if ssAlt
in shift
then
begin
(* Alt needs special treatment since a bit in lparam needs also be set *)
pKeyBuffers^[0][VK_MENU] := $80;
lParam := lParam
or $20000000;
end;
if ssCtrl
in shift
then
pKeyBuffers^[0][VK_CONTROL] := $80;
if ssLeft
in shift
then
pKeyBuffers^[0][VK_LBUTTON] := $80;
if ssRight
in shift
then
pKeyBuffers^[0][VK_RBUTTON] := $80;
if ssMiddle
in shift
then
pKeyBuffers^[0][VK_MBUTTON] := $80;
(* make out new key state array the active key state map *)
SetKeyboardState(pKeyBuffers^[0]);
(* post the key messages *)
if ssAlt
in Shift
then
begin
PostMessage(hWindow, WM_SYSKEYDOWN, key, lParam);
PostMessage(hWindow, WM_SYSKEYUP, key, lParam
or $C0000000);
end
else
begin
PostMessage(hWindow, WM_KEYDOWN, key, lParam);
PostMessage(hWindow, WM_KEYUP, key, lParam
or $C0000000);
end;
(* process the messages *)
Application.ProcessMessages;
(* restore the old key state map *)
SetKeyboardState(pKeyBuffers^[1]);
finally
(* free the memory for the key state buffers *)
if pKeyBuffers <>
nil then
Dispose(pKeyBuffers);
end;
{ If }
end;
end;
{ PostKeyEx }