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