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Delphi source code for Windows >> Simulate the pressing of keyboard keys


Category: Windows
Title: Simulate the pressing of keyboard keys
Author: swissdelphicenter.ch
Date added: 15.03.2006
Hits: 82193


{1. PostKeyEx32 function}

procedure PostKeyEx32(key: Word; const shift: TShiftState; specialkey: Boolean);
{************************************************************
* Procedure PostKeyEx32
*
* Parameters:
*  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.
* Description:
*  Uses keybd_event to manufacture a series of key events matching
*  the passed parameters. The events go to the control with focus.
*  Note that for characters key is always the upper-case version of
*  the character. Sending without any modifier keys will result in
*  a lower-case character, sending it with [ssShift] will result
*  in an upper-case character!
************************************************************}

type
  TShiftKeyInfo = record
    shift: Byte;
    vkey: Byte;
  end;
  byteset = set of 0..7;
const
  shiftkeys: array [1..3] of TShiftKeyInfo =
    ((shift: Ord(ssCtrl); vkey: VK_CONTROL),
    (shift: Ord(ssShift); vkey: VK_SHIFT),
    (shift: Ord(ssAlt); vkey: VK_MENU));
var
  flag: DWORD;
  bShift: ByteSet absolute shift;
  i: Integer;
begin
  for i := 1 to 3 do
  begin
    if shiftkeys[i].shift in bShift then
      keybd_event(shiftkeys[i].vkey, MapVirtualKey(shiftkeys[i].vkey, 0), 0, 0);
  end; { For }
  if specialkey then
    flag := KEYEVENTF_EXTENDEDKEY
  else
    flag := 0;
  keybd_event(key, MapvirtualKey(key, 0), flag, 0);
  flag := flag or KEYEVENTF_KEYUP;
  keybd_event(key, MapvirtualKey(key, 0), flag, 0);
  for i := 3 downto 1 do
  begin
    if shiftkeys[i].shift in bShift then
      keybd_event(shiftkeys[i].vkey, MapVirtualKey(shiftkeys[i].vkey, 0),
        KEYEVENTF_KEYUP, 0);
  end; { For }
end; { PostKeyEx32 }

procedure TForm1.Button1Click(Sender: TObject);
begin
  PostKeyEx32(VK_LWIN, [], False);
  PostKeyEx32(Ord('D'), [], False);
  PostKeyEx32(Ord('C'), [ssctrl, ssAlt], False);
end;
{************************************************************}
{2. With keybd_event API}

procedure TForm1.Button1Click(Sender: TObject);
begin
  {or you can also try this simple example to send any
   amount of keystrokes at the same time. }

  {Pressing the A Key and showing it in the Edit1.Text}
  Edit1.SetFocus;
  keybd_event(VK_SHIFT, 0, 0, 0);
  keybd_event(Ord('A'), 0, 0, 0);
  keybd_event(VK_SHIFT, 0, KEYEVENTF_KEYUP, 0);
  {Presses the Left Window Key and starts the Run}
  keybd_event(VK_LWIN, 0, 0, 0);
  keybd_event(Ord('R'), 0, 0, 0);
  keybd_event(VK_LWIN, 0, KEYEVENTF_KEYUP, 0);
end;
{***********************************************************}
{3. With keybd_event API}

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 }

procedure TForm1.Button1Click(Sender: TObject);
var
  targetWnd: HWND;
begin
  targetWnd := FindWindow('notepad', nil)
    if targetWnd <> 0 then
    begin
      PostKeyExHWND(targetWnd, Ord('I'), [ssAlt], False);
  end;
end;
{***********************************************************}
{3. With SendInput API}

procedure TForm1.Button1Click(Sender: TObject);
const
   Str: string = 'writing writing writing';
var
  Inp: TInput;
  I: Integer;
begin
  Edit1.SetFocus;
  for I := 1 to Length(Str) do
  begin
    Inp.Itype := INPUT_KEYBOARD;
    Inp.ki.wVk := Ord(UpCase(Str[i]));
    Inp.ki.dwFlags := 0;
    SendInput(1, Inp, SizeOf(Inp));
    Inp.Itype := INPUT_KEYBOARD;
    Inp.ki.wVk := Ord(UpCase(Str[i]));
    Inp.ki.dwFlags := KEYEVENTF_KEYUP;
    SendInput(1, Inp, SizeOf(Inp));
    Application.ProcessMessages;
    Sleep(80);
  end;
end;

procedure SendAltTab;
var
  KeyInputs: array of TInput;
  KeyInputCount: Integer;
  
procedure KeybdInput(VKey: Byte; Flags: DWORD);
  begin
    Inc(KeyInputCount);
    SetLength(KeyInputs, KeyInputCount);
    KeyInputs[KeyInputCount - 1].Itype := INPUT_KEYBOARD;
    with  KeyInputs[KeyInputCount - 1].ki do
    begin
      wVk := VKey;
      wScan := MapVirtualKey(wVk, 0);
      dwFlags := KEYEVENTF_EXTENDEDKEY;
      dwFlags := Flags or dwFlags;
      time := 0;
      dwExtraInfo := 0;
    end;
  end;
begin
  KeybdInput(VK_MENU, 0);                // Alt
  KeybdInput(VK_TAB, 0);                 // Tab
  KeybdInput(VK_TAB, KEYEVENTF_KEYUP);   // Tab
  KeybdInput(VK_MENU, KEYEVENTF_KEYUP); // Alt
  SendInput(KeyInputCount, KeyInputs[0], SizeOf(KeyInputs[0]));
end;


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