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VC ListCtrl中嵌入进度条

2012-09-12 19:49 工业·编程 ⁄ 共 3439字 ⁄ 字号 暂无评论

VC中在listctrl中嵌入进度条,截图如下:

其实要实现这个非常容易,以下是自绘ListCtrl的代码,首先继承CListCtrl,
然后增加函数OnCustomDraw:
void CProcessList::OnCustomDraw(NMHDR *pNMHDR, LRESULT *pResult)
{
//draw each item.set txt color,bkcolor....
NMLVCUSTOMDRAW* pLVCD = reinterpret_cast<NMLVCUSTOMDRAW*>(pNMHDR);
// Take the default processing unless we set this to something else below.
*pResult = CDRF_DODEFAULT;
// First thing - check the draw stage. If it’s the control’s prepaint
// stage, then tell Windows we want messages for every item.
if (pLVCD->nmcd.dwDrawStage == CDDS_PREPAINT)
{
  *pResult = CDRF_NOTIFYITEMDRAW;
}
else if (pLVCD->nmcd.dwDrawStage == CDDS_ITEMPREPAINT)
{
  // This is the notification message for an item.  We’ll request
  // notifications before each subitem’s prepaint stage.
  *pResult = CDRF_NOTIFYSUBITEMDRAW;
}
else if (pLVCD->nmcd.dwDrawStage == (CDDS_ITEMPREPAINT | CDDS_SUBITEM))
{
  // This is the prepaint stage for a subitem. Here’s where we set the
  // item’s text and background colors. Our return value will tell
  // Windows to draw the subitem itself, but it will use the new colors
  // we set here.
  int nItem = static_cast<int> (pLVCD->nmcd.dwItemSpec);
  int nSubItem = pLVCD->iSubItem;
  if(nSubItem != 2)//这里我只重绘第二列
   return;

  COLORREF crText  = ::GetSysColor(COLOR_WINDOWFRAME);
  COLORREF crBkgnd = ::GetSysColor(COLOR_WINDOW);
  CDC* pDC = CDC::FromHandle(pLVCD->nmcd.hdc);
  CRect rect;
  GetSubItemRect(nItem, nSubItem, LVIR_BOUNDS, rect);
  if (GetItemState(nItem, LVIS_SELECTED))
   DrawText(nItem, nSubItem, pDC, ::GetSysColor(COLOR_HIGHLIGHT), 
   ::GetSysColor(COLOR_HIGHLIGHT), rect);
  else
   DrawText(nItem, nSubItem, pDC, crText, crBkgnd, rect);

  *pResult = CDRF_SKIPDEFAULT; // We’ve painted everything.
}
}

然后为该函数增加消息映射(#add 其实是消息反射):
ON_NOTIFY_REFLECT(NM_CUSTOMDRAW, OnCustomDraw)
最后我们为画进度条而努力,这里程序中把进度存在ItemData中。
void CProcessList::DrawText(int nItem, 
        int nSubItem, 
        CDC *pDC, 
        COLORREF crText, 
        COLORREF crBkgnd, 
        CRect &rect)
{
ASSERT(pDC);
pDC->FillSolidRect(&rect, crBkgnd);
int nProcess = GetItemData(nItem);
CRect procRect = rect;
pDC->Rectangle(procRect);

procRect.left += 1;
procRect.bottom -= 1;
procRect.top += 1;
procRect.right = procRect.left + rect.Width() * nProcess / 100;
CBrush brush(RGB(255,0,0));
pDC->FillRect(&procRect, &brush);
CString str;
str.Format("%d%%", nProcess);
if (!str.IsEmpty())
{
  UINT nFormat = DT_VCENTER | DT_SINGLELINE | DT_CENTER;
  pDC->SetBkMode(TRANSPARENT);
  pDC->SetTextColor(crText);
  pDC->SetBkColor(crBkgnd);
  pDC->DrawText(str, &rect, nFormat);
}
}

上面用到一个结构,是存放于ItemData中用来表示进度和步长的:
typedef struct _ProcessLCI_Data_
{
            int  nProportion;
int  nStep;
} PLCIDATA, *LPPLCIDATA;

接下来就是在容器中使用继承的ListCtrl了,这里使用对话框,在一个定时器中模拟进度的变化(其它的初始化和清除就不罗嗦了):

void CListCtrlProcessDlg::OnTimer(UINT nIDEvent)
{
      if(nIDEvent == TIMER_PROCESS)
      {
                    BOOL bPaint = FALSE;
         for(int i = 0; i < m_listProcess.GetItemCount(); ++i)
          {
                     LPPLCIDATA pIData = (LPPLCIDATA)m_listProcess.GetItemData(i);
                     if(pIData->nProportion >= 100)
                              continue;
                     bPaint = TRUE;
                     if(pIData->nProportion + pIData->nStep > 100)
                     {
                               pIData->nProportion = 100;
                     }
                     else
                     {
                               pIData->nProportion += pIData->nStep;
                     }
           }
           if(bPaint)
m_listProcess.Invalidate(FALSE);
     }
     CDialog::OnTimer(nIDEvent);
}

这里有个奇怪的问题,在VC6中不调上面的Invalidate(),只要TIMMER发生,进度条都会自动刷新。但在VC71上编译,如果不调Invalidate(),根本不刷新???不解!!!
从运行的结果看,效果还不错。VC6编译的就是满100%后进度条还是不停的闪烁;而VC71就不会了,因为没有调Invalidate()???

怎么样?很简单吧,其实使用VC开发界面也非常迅速的,虽然还是觉得MFC的封装有JAVA界面库封装得那么好该多好啊

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