unit Unit1;

interface

uses

  SysUtils, WinTypes, WinProcs, Messages, Classes, Graphics, Controls,
  Forms, Dialogs, StdCtrls;

type

  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure FormKeyPress(Sender: TObject; var Key: Char);
  private
    AppInst: THandle;
    AppWind: THandle;
  public
    { Public declarations }
  end;

var

  Form1: TForm1;

implementation

{$R *.DFM}

uses ShellAPI;

procedure SendShift(H: HWnd; Down: Boolean);
var
  vKey, ScanCode, wParam: Word;

  lParam: longint;
begin

  vKey := $10;
  ScanCode := MapVirtualKey(vKey, 0);
  wParam := vKey or ScanCode shl 8;
  lParam := longint(ScanCode) shl 16 or 1;
  if not (Down) then
    lParam := lParam or $C0000000;
  SendMessage(H, WM_KEYDOWN, vKey, lParam);
end;

procedure SendCtrl(H: HWnd; Down: Boolean);
var
  vKey, ScanCode, wParam: Word;

  lParam: longint;
begin

  vKey := $11;
  ScanCode := MapVirtualKey(vKey, 0);
  wParam := vKey or ScanCode shl 8;
  lParam := longint(ScanCode) shl 16 or 1;
  if not (Down) then
    lParam := lParam or $C0000000;
  SendMessage(H, WM_KEYDOWN, vKey, lParam);
end;

procedure SendKey(H: Hwnd; Key: char);
var
  vKey, ScanCode, wParam: Word;

  lParam, ConvKey: longint;
  Shift, Ctrl: boolean;
begin

  ConvKey := OemKeyScan(ord(Key));
  Shift := (ConvKey and $00020000) <> 0;
  Ctrl := (ConvKey and $00040000) <> 0;
  ScanCode := ConvKey and $000000FF or $FF00;
  vKey := ord(Key);
  wParam := vKey;
  lParam := longint(ScanCode) shl 16 or 1;
  if Shift then
    SendShift(H, true);
  if Ctrl then
    SendCtrl(H, true);
  SendMessage(H, WM_KEYDOWN, vKey, lParam);
  SendMessage(H, WM_CHAR, vKey, lParam);
  lParam := lParam or $C0000000;
  SendMessage(H, WM_KEYUP, vKey, lParam);
  if Shift then
    SendShift(H, false);
  if Ctrl then
    SendCtrl(H, false);
end;

function EnumFunc(Handle: HWnd; TF: TForm1): Bool; far;
begin

  TF.AppWind := 0;
  if GetWindowWord(Handle, GWW_HINSTANCE) = TF.AppInst then
    TF.AppWind := Handle;
  result := (TF.AppWind = 0);
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  Text: array[0..255] of char;
begin

  AppInst := ShellExecute(Handle, 'open', 'notepad.exe', nil, '', SW_NORMAL);
  EnumWindows(@EnumFunc, longint(self));
  AppWind := GetWindow(AppWind, GW_CHILD);
end;

procedure TForm1.Button2Click(Sender: TObject);
begin

  SendKey(AppWind, 'T');
  SendKey(AppWind, 'e');
  SendKey(AppWind, 's');
  SendKey(AppWind, 't');
end;

procedure TForm1.FormKeyPress(Sender: TObject; var Key: Char);
begin

  if AppWind <> 0 then
    SendKey(AppWind, Key);
end;

end.