无法实现选中文本

Question

delphi模拟按键 
       keybd_event(42,mapvirtualkey(42,0),0,0);
        keybd_event(39,mapvirtualkey(39,0),0,0);
        keybd_event(39,mapvirtualkey(39,0),keyeventf_keyup,0);
        keybd_event(39,mapvirtualkey(39,0),0,0);
        keybd_event(39,mapvirtualkey(39,0),keyeventf_keyup,0);
        keybd_event(39,mapvirtualkey(39,0),0,0);
        keybd_event(39,mapvirtualkey(39,0),keyeventf_keyup,0);
        keybd_event(42,mapvirtualkey(42,0),keyeventf_keyup,0);
用段程序模拟光标先放在文本中的任意一处，按住SHIFT再按右右右选中文本中的三个字符，但这段程序无法实现，有知道为什么的吗？

Answer 1

未设置焦点
前面加 edit1.setfocuse  

Answer 2

我种开贴了http://topic.csdn.net/u/20080824/19/63eb2254-c0cb-4393-b55f-833e5c3dcd65.html

Answer 3

procedure TForm1.Button1Click(Sender: TObject);
var
 i:byte;
begin
  sleeP(2000);
  for i:=1 to 3 do
  begin
    keybd_event(VK_SHIFT,0,KEYEVENTF_EXTENDEDKEY or 0,0);
    keybd_event(VK_RIGHT,0,KEYEVENTF_EXTENDEDKEY or 0,0);
    keybd_event(VK_RIGHT,0,KEYEVENTF_EXTENDEDKEY or KEYEVENTF_KEYUP,0);
    keybd_event(VK_SHIFT,0,KEYEVENTF_EXTENDEDKEY or KEYEVENTF_KEYUP,0);
  end;
end;