bool key_backquote = false;
TForm1 *Form1;
//-----------------------
__fastcall TForm1::TForm1(TComponent* Owner)
        : TForm(Owner)
{
   Timer1->Interval = 1000;   //一秒鐘
   Timer1->Enabled = false;
   Form1->KeyPreview = true;
}
//-----------------------    void __fastcall TForm1::FormKeyPress(TObject *Sender, char &Key)
{
   if (Key == 0x60) {   //循環控制(送出與停止)
     key_backquote = !key_backquote;
     Timer1->Enabled = key_backquote;
     Key = 0; }
}
//-----------------------    void __fastcall TForm1::Timer1Timer(TObject *Sender)
{
   keybd_event(0x41,0,0,0);
   keybd_event(0x41,0,KEYEVENTF_KEYUP,0);
}