void LineScroll( int nLines, int nChars = 0 );
richedit.perform(wm_vscroll,sb_linedown,0);
richedit.perform(em_scrollcaret,0,0);可以把光标所在行滚入视区;
richedit.perform(wm_vscroll,sb_linedown,0);
richedit.perform(em_scrollcaret,0,0);可以把光标所在行滚入视区;
SendMessage(WM_KEYDOWN,VK_DOWN,0);