c++ - 如何绘制非客户区？

Question

我希望能够在菜单栏的右侧，在窗口的非客户区进行一些绘图。

这可能吗，使用 C++/MFC？

Answer 1

查理用 WM_NCPAINT 找到了答案。如果您使用的是 MFC，代码将如下所示:

// in the message map
ON_WM_NCPAINT()

// ...

void CMainFrame::OnNcPaint()
{
   // still want the menu to be drawn, so trigger default handler first
   Default();

   // get menu bar bounds
   MENUBARINFO menuInfo = {sizeof(MENUBARINFO)};
   if ( GetMenuBarInfo(OBJID_MENU, 0, &menuInfo) )
   {
      CRect windowBounds;
      GetWindowRect(&windowBounds);
      CRect menuBounds(menuInfo.rcBar);
      menuBounds.OffsetRect(-windowBounds.TopLeft());

      // horrible, horrible icon-drawing code. Don't use this. Seriously.
      CWindowDC dc(this);
      HICON appIcon = (HICON)::LoadImage(AfxGetResourceHandle(), MAKEINTRESOURCE(IDR_MAINFRAME), IMAGE_ICON, 16, 16, LR_DEFAULTCOLOR);
      ::DrawIconEx(dc, menuBounds.right-18, menuBounds.top+2, appIcon, 0,0, 0, NULL, DI_NORMAL);
      ::DestroyIcon(appIcon);
   }
}