Window SubClassing另类运用（之二）[6]

                         hinstance, nil);

  sendmessage(wndcombo, wm_setfont,

              sendmessage(awnd, wm_getfont, 0, 0),

              1);

  oldstyle := getwindowlong(wnd, gwl_style);

  setwindowlong(wnd, gwl_style, oldstyle or tvs_showselalways);

  saverect := rc;

  wnd := getwindow(awnd, gw_child);

  while iswindow(wnd) do begin

    getwindowrect(wnd, rc);

    screentoclient(awnd, rc.topleft);

    screentoclient(awnd, rc.bottomright);

    if (wnd<>wndcombo) and (rc.top>=saverect.top) then

       setwindowpos(wnd, hwnd_notopmost, rc.left, rc.top+40, 0, 0, swp_nosize or swp_nozorder);

    wnd := getwindow(wnd, gw_hwndnext);

  end;

  getwindowrect(awnd, rc);

  setwindowpos(awnd, hwnd_notopmost, 0, 0, rc.right-rc.left, rc.bottom-rc.top+40, swp_nomove or swp_nozorder);

如果你过去很少用api写程序，那么这些代码可能让你看得有点头晕。基本上上述程序完成如下的工作：

（1）计算treeview在窗口中的位置；