private ImageSource GetDisplayIcon(IconSize size)
{
ImageSource icon = null;
IShellItemImageFactory imageFactory = GetImageFactory(AbsolutePidl);
if (imageFactory == null)
{
icon = IconImageConverter.GetDefaultIcon();
}
else
{
try
{
int iconPoints = IconHelper.GetSize(size);
SIZE imageSize = new SIZE {
cx = (int)(iconPoints * DpiHelper.DpiScale), cy = (int)(iconPoints * DpiHelper.DpiScale)
};
IntPtr hBitmap = IntPtr.Zero;
SIIGBF flags = 0;
if (size == IconSize.Small)
{
// for 16pt icons, thumbnails are too small
flags = SIIGBF.ICONONLY;
}
if (imageFactory?.GetImage(imageSize, flags, out hBitmap) == NativeMethods.S_OK)
{
if (hBitmap != IntPtr.Zero)
{
icon = IconImageConverter.GetImageFromHBitmap(hBitmap);
}
}
}
catch (Exception e)
{
ShellLogger.Error($"ShellItem: Unable to get icon from ShellItemImageFactory: {e.Message}");
}
finally
{
Marshal.FinalReleaseComObject(imageFactory);
}
}
if (icon == null)
{
// Fall back to SHGetFileInfo
icon = IconImageConverter.GetImageFromAssociatedIcon(AbsolutePidl, size);
}
if (icon == null)
{
icon = IconImageConverter.GetDefaultIcon();
}
return(icon);
}
public ShellItemImageFactory(IShellItemImageFactory shllItemImageFactoryInterface)
{
Contract.Requires <ArgumentNullException>(shllItemImageFactoryInterface != null);
this.shllItemImageFactoryInterface = shllItemImageFactoryInterface;
this.SizeOption = ShellItemImageSizeOptions.ResizeToFit;
this.RetrievalOption = ShellItemImageRetrievalOptions.Default;
this.FormatOption = ShellItemImageFormatOptions.Default;
}
public static extern int SHCreateItemFromParsingNameIShellItemImageFactory(
[In][MarshalAs(UnmanagedType.LPWStr)] string pszPath,
[In] IntPtr pbc,
[In][MarshalAs(UnmanagedType.LPStruct)] Guid riid,
[Out][MarshalAs(UnmanagedType.Interface, IidParameterIndex = 2)] out IShellItemImageFactory ppv);
public Bitmap LoadThumbnailFromImageFactory(string filename, Size requestedSize, bool onlyThumbnail)
{
if (!System.IO.Directory.Exists(filename) && !System.IO.File.Exists(filename))
{
return(null);
}
Bitmap bm1 = null;
IntPtr hbitmap = IntPtr.Zero;
SIZE sz = new SIZE(requestedSize.Width, requestedSize.Height);
IShellFolder desktop = null;
IntPtr pidlMain = IntPtr.Zero;
IShellItem shellItem = null;
IShellItemImageFactory ppsiShellItemImageFactory = null;
try
{
Shell32.SHGetDesktopFolder(ref desktop);
int cParsed = 0;
int pdwAttrib = 0;
desktop.ParseDisplayName(IntPtr.Zero, IntPtr.Zero, filename, out cParsed, out pidlMain, out pdwAttrib);
//Shell32.SHCreateItemFromIDList(pidlMain, uuidIShellItem, out shellItem);
Shell32.SHCreateShellItem(IntPtr.Zero, null, pidlMain, out shellItem);
ppsiShellItemImageFactory = (IShellItemImageFactory)shellItem;
if (onlyThumbnail)
{
ppsiShellItemImageFactory.GetImage(sz, SIIGBF.SIIGBF_BIGGERSIZEOK | SIIGBF.SIIGBF_THUMBNAILONLY, out hbitmap);
}
else
{
ppsiShellItemImageFactory.GetImage(sz, SIIGBF.SIIGBF_BIGGERSIZEOK, out hbitmap);
}
bm1 = GetBitmapFromHbitmap(hbitmap);
}
catch (InvalidCastException)
{
Debug.Write(" Did not support IShellItemImageFactory\r\n");
}
catch (Exception e)
{
Debug.Write(" Exception extracting image from IShellItemImageFactory: " + e.Message + "\r\n");
}
finally
{
if (ppsiShellItemImageFactory != null)
{
Marshal.ReleaseComObject(ppsiShellItemImageFactory);
ppsiShellItemImageFactory = null;
}
if (shellItem != null)
{
Marshal.ReleaseComObject(shellItem);
shellItem = null;
}
if (pidlMain != IntPtr.Zero)
{
Allocator.Free(pidlMain);
pidlMain = IntPtr.Zero;
}
if (desktop != null)
{
Marshal.ReleaseComObject(desktop);
desktop = null;
}
if (_allocator != null)
{
Marshal.ReleaseComObject(_allocator);
_allocator = null;
}
}
return(bm1);
}
private static extern int SHCreateItemFromParsingName(string path, IntPtr pbc, [MarshalAs(UnmanagedType.LPStruct)] Guid riid, out IShellItemImageFactory factory);
public static extern void SHCreateItemFromIDList(
[In] IntPtr pidl,
[In][MarshalAs(UnmanagedType.LPStruct)] Guid riid,
[Out][MarshalAs(UnmanagedType.Interface, IidParameterIndex = 2)] out IShellItemImageFactory ppv);
