Trying to Create a ToolBar with an ImageList, not working

will be helpful for those in need I know you've probably resolved it by your own, but I've been playing a bit with converter.exe some time ago, so I hope this is what you were looking for.
Set the -alpha parameter to the background flag, what means that every fully transparent pixel will be set to the background color, while leaving it fully transparent. And set also the -background to a certain color RGB(192,192,192), so the previously transparent pixels will get this color.

convert.exe -resize 32x32 -alpha background -background RGB(192,192,192) @imagelist32.txt +append BMP3:toolbarlarge.bmp

will help you Like Малъ Скрылевъ said, ImageList is based on Enumerable. That means that you can just use @il += @list_being_added.

seems to work fine Edit ----------
First parameter in Gdiplus::GetHBITMAP should be the background color. Using RGB(0, 0, 0) as background color causes the semi-transparent pixels to match with black.

{
    CGdiPlusBitmapResource gdibmp;
    if (gdibmp.Load(IDB_RIBBON_HOMELARGE, _T("PNG"), AfxGetResourceHandle()))
    {
        HBITMAP hBitmap;
        gdibmp.m_pBitmap->GetHBITMAP(Gdiplus::Color::Transparent, &hBitmap);
        ImageList_AddMasked(*pList, hBitmap, 0);
    }
}

{
    CGdiPlusBitmapResource gdibmp;
    if (gdibmp.Load(id, _T("PNG"), AfxGetResourceHandle()))
    {
        //resize image to 32x32 pixels
        Gdiplus::Bitmap newBmp(32, 32, PixelFormat32bppPARGB);
        double oldh = (double)gdibmp.m_pBitmap->GetHeight();
        double oldw = (double)gdibmp.m_pBitmap->GetWidth();
        double neww = 32;
        double newh = 32;

        double ratio = oldw / oldh;
        if (oldw > oldh)
            newh = neww / ratio;
        else
            neww = newh * ratio;

        Gdiplus::Graphics graphics(&newBmp);
        graphics.SetInterpolationMode(Gdiplus::InterpolationMode::InterpolationModeHighQualityBicubic);
        graphics.SetSmoothingMode(Gdiplus::SmoothingModeAntiAlias);
        graphics.DrawImage(gdibmp.m_pBitmap, 0, 0, (int)neww, (int)newh);

        //add `newBmp` to image list
        HBITMAP hBitmap;
        newBmp.GetHBITMAP(Gdiplus::Color::Transparent, &hBitmap);
        ImageList_AddMasked(m_ImageList, hBitmap, 0);
    }
}

HICON hicon;
m_pBitmap.Load(IDB_RIBBON_HOMELARGE, _T("PNG"), AfxGetResourceHandle());
m_pBitmap.m_pBitmap->GetHICON(&hicon);
pList->Add(hicon);

help you fix your problem It looks like you're trying to remove the images from the Labels ImageList that you've just assigned to it. You will eventually end up with 0 entries in the ImageList and Labels still referencing indexes. your assignment of imgLbl.ImageList is a reference to the already existing ImageList object, it is not cloning it and as such when you remove an entry from its list it is removing it for every label already assigned the instance. You want to clone the list (or better yet) maintain 1 full list and ensure you dont pick the same number twice.

should help you out Please try this this this code will rad all files from a folder and add show it in the listview . The you just need to change the logic for reading it form DB .

    private void Form1_Load(object sender, EventArgs e)
    {
        var folderPath = @"c:\images\";
        DirectoryInfo dir = new DirectoryInfo(folderPath);

        var imageList = new ImageList();
        foreach (FileInfo file in dir.GetFiles())
        {
            try
            {
               imageList.Images.Add(Image.FromFile(file.FullName));
            }
            catch{
                Console.WriteLine("This is not an image file");
            }
        }
        this.listView1.View = View.LargeIcon;
        imageList.ImageSize = new Size(128, 128);
        this.listView1.LargeImageList = imageList;

        for (int j = 0; j < imageList.Images.Count; j++)
        {
            ListViewItem item = new ListViewItem();
            item.ImageIndex = j;
            this.listView1.Items.Add(item);
        }
    }