Scaling a CBitmap - what am I doing wrong?
- by Smashery
I've written the following code, which attempts to take a 32x32 bitmap (loaded through MFC's Resource system) and turn it into a 16x16 bitmap, so they can be used as the big and small CImageLists for a CListCtrl. However, when I open the CListCtrl, all the icons are black (in both small and large view). Before I started playing with resizing, everything worked perfectly in Large View.
What am I doing wrong?
// Create the CImageLists
if (!m_imageListL.Create(32,32,ILC_COLOR24, 1, 1))
{
throw std::exception("Failed to create CImageList");
}
if (!m_imageListS.Create(16,16,ILC_COLOR24, 1, 1))
{
throw std::exception("Failed to create CImageList");
}
// Fill the CImageLists with items loaded from ResourceIDs
int i = 0;
for (std::vector<UINT>::iterator it = vec.begin(); it != vec.end(); it++, i++)
{
CBitmap* bmpBig = new CBitmap();
bmpBig->LoadBitmap(*it);
CDC bigDC;
bigDC.CreateCompatibleDC(m_itemList.GetDC());
bigDC.SelectObject(bmpBig);
CBitmap* bmpSmall = new CBitmap();
bmpSmall->CreateBitmap(16, 16, 1, 24, 0);
CDC smallDC;
smallDC.CreateCompatibleDC(&bigDC);
smallDC.SelectObject(bmpSmall);
smallDC.StretchBlt(0, 0, 32, 32, &bigDC, 0, 0, 16, 16, SRCCOPY);
m_imageListL.Add(bmpBig, RGB(0,0,0));
m_imageListS.Add(bmpSmall, RGB(0,0,0));
}
m_itemList.SetImageList(&m_imageListS, LVSIL_SMALL);
m_itemList.SetImageList(&m_imageListL, LVSIL_NORMAL);
