TrackBar 自绘 NM_CUSTOMDRAW ？

Question

大家看一下，为什么我一直只收到 CDDS_PREPAINT, 收不到CDDS_ITEMPREPAINT 呢？
case WM_NOTIFY:
{
LPNMHDR lpHdr = (LPNMHDR)lParam; switch (lpHdr->idFrom)
{
case IDTRACK1:
{
if (lpHdr->code == NM_CUSTOMDRAW)
{
LPNMCUSTOMDRAW lpCustomDraw = (LPNMCUSTOMDRAW)lParam; switch (lpCustomDraw->dwDrawStage)
{

case CDDS_PREPAINT:
MessageBox(NULL, TEXT("CDDS_PREPAINT"), TEXT("NOTE"), MB_OK);
return CDRF_NOTIFYITEMDRAW;
                        
case CDDS_ITEMPREPAINT:
MessageBox(NULL, TEXT("CDDS_ITEMPREPAINT"), TEXT("NOTE"), MB_OK);
return CDRF_DODEFAULT;
                                                default:
                                                        return TRUE;
}
}
                               case IDTRACK2:
                                    ............................
}

Answer 1

我看了一篇，《Visual C++2005中开发自定义绘图控件》，你搜一下。
感觉问题出在这一点代码应该出现在控件的消息（NM_CUSTOMDRAW）响应中，而不是在父窗口。
switch (lpCustomDraw->dwDrawStage)
{case CDDS_PREPAINT:
MessageBox(NULL, TEXT("CDDS_PREPAINT"), TEXT("NOTE"), MB_OK);
return CDRF_NOTIFYITEMDRAW;
    
case CDDS_ITEMPREPAINT:
MessageBox(NULL, TEXT("CDDS_ITEMPREPAINT"), TEXT("NOTE"), MB_OK);
return CDRF_DODEFAULT;
  default:
  return TRUE;
}

Answer 2

http://topic.csdn.net/u/20070910/14/928362f5-1216-46e8-8eaf-34f6941715e1.html
看这个帖子