C++ CComboBox::SetHorizontalExtent方法代码示例

CComboBox* CSHListCtrl::ShowInPlaceComboBox(int nItem, int nSubitem,DWORD dwStyle)
{
	// The returned pointer should not be saved
	// Make sure that the item is visible
	// My code start here
	if (!EnsureVisible(nItem, TRUE) )
		return NULL;
	// Make sure that nCol is valid 
	CHeaderCtrl* pHeader = (CHeaderCtrl*)GetDlgItem(0);
	int nColumnCount = pHeader->GetItemCount();
	if( nSubitem >= nColumnCount || GetColumnWidth(nSubitem) < 10 ) 
		return NULL;
	// Get the column offset
	int offset = 0;
	for(int i = 0; i < nSubitem; i++)
		offset += GetColumnWidth(i);

	CRect rect;
	GetItemRect(nItem, &rect, LVIR_BOUNDS);

	// Now scroll if we need to expose the column
	CRect rcClient;
	GetClientRect(&rcClient);
	if(offset + rect.left < 0 || offset + rect.left > rcClient.right)
	{
		CSize size;
		size.cx = offset + rect.left;
		size.cy = 0;
		Scroll(size);
		rect.left -= size.cx;
	}

	rect.left += offset;
	rect.right = rect.left + GetColumnWidth( nSubitem ) ;
	int height = rect.bottom - rect.top;
	rect.bottom += 22 * height;
	if (rect.right > rcClient.right)
		rect.right = rcClient.right;

	dwStyle |= WS_CHILD | WS_VISIBLE | WS_VSCROLL | CBS_DISABLENOSCROLL;

	CComboBox* pList = new CSHInPlaceComboBox(nItem, nSubitem);
	pList->Create(dwStyle, rect, this, IDC_INPLACE_COMBOBOX);
	pList->SetItemHeight(-1, height);
	pList->SetHorizontalExtent(GetColumnWidth(nSubitem));

	CString strWindowText = GetItemText(nItem, nSubitem);
	if(dwStyle & CBS_DROPDOWN && !(dwStyle & CBS_DROPDOWNLIST))
	{
		CEdit* m_pEdit = new CEdit();
		m_pEdit->SubclassWindow(pList->GetDlgItem(1001)->GetSafeHwnd());
		m_pEdit->SetWindowText(strWindowText);
		m_pEdit->SetSel(0,-1);
	}

	return pList;
	// My code end here
}

void UpdateHorzExtent(CComboBox &rctlComboBox, int iIconWidth)
{
	int iItemCount = rctlComboBox.GetCount();
	if (iItemCount > 0)
	{
		CDC *pDC = rctlComboBox.GetDC();
		if (pDC != NULL)
		{
			// *** To get *ACCURATE* results from 'GetOutputTextExtent' one *MUST*
			// *** explicitly set the font!
			CFont *pOldFont = pDC->SelectObject(rctlComboBox.GetFont());

			CString strItem;
			int iMaxWidth = 0;
			for (int i = 0; i < iItemCount; i++)
			{
				rctlComboBox.GetLBText(i, strItem);
				int iItemWidth = pDC->GetOutputTextExtent(strItem, strItem.GetLength()).cx;
				if (iItemWidth > iMaxWidth)
					iMaxWidth = iItemWidth;
			}
			
			pDC->SelectObject(pOldFont);
			rctlComboBox.ReleaseDC(pDC);

			// Depending on the string (lot of "M" or lot of "i") sometime the
			// width is just a few pixels too small!
			iMaxWidth += 4;
			if (iIconWidth)
				iMaxWidth += 2 + iIconWidth + 2;
			rctlComboBox.SetHorizontalExtent(iMaxWidth);
			if (rctlComboBox.GetDroppedWidth() < iMaxWidth)
				rctlComboBox.SetDroppedWidth(iMaxWidth);
		}
	}
	else
		rctlComboBox.SetHorizontalExtent(0);
}

CComboBox* CMySuperGrid::ShowList(int nItem, int nCol, CStringList *lstItems)
{
	CString strFind = GetItemText(nItem, nCol);

	//basic code start
	CRect rect;
	int offset = 0;
	// Make sure that the item is visible
	if( !EnsureVisible(nItem, TRUE)) return NULL;
	GetSubItemRect(nItem, nCol, LVIR_BOUNDS, rect);
	// Now scroll if we need to expose the column
	CRect rcClient;
	GetClientRect(rcClient);
	if( offset + rect.left < 0 || offset + rect.left > rcClient.right )
	{
		CSize size;
		size.cx = offset + rect.left;
		size.cy = 0;
		Scroll(size);
		rect.left -= size.cx;
	}
	
	rect.left += offset;	
	rect.right = rect.left + GetColumnWidth(nCol);
	if(rect.right > rcClient.right) 
	   rect.right = rcClient.right;
	//basic code end

	rect.bottom += 10 * rect.Height();//dropdown area
	
	DWORD dwStyle =  WS_CHILD | WS_VISIBLE | WS_VSCROLL | WS_HSCROLL|CBS_DROPDOWNLIST | CBS_DISABLENOSCROLL;
	CComboBox *pList = new CComboInListView(nItem, nCol, lstItems);
	pList->Create(dwStyle, rect, this, IDC_COMBOBOXINLISTVIEW);
	pList->ModifyStyleEx(0,WS_EX_CLIENTEDGE);//can we tell at all
	pList->SetHorizontalExtent(CalcHorzExtent(pList, lstItems));
	pList->ShowDropDown();
	pList->SelectString(-1, strFind.GetBuffer(1));
	// The returned pointer should not be saved
	return pList;
}