procedure TForm1.Button1Click(Sender: TObject);
var
wnd: Hwnd;
s: string;
i: integer;
begin
wnd := FindWindow('notepad', nil);
if wnd<>0 then
begin
wnd := FindWindowEx(wnd,0,'Edit',nil);
s := 'hello, world';
for i := 1 to length(s) do
SendMessage(wnd, WM_CHAR, ord(s), 0);
end
else ShowMessage('notepad not find');
end;
