public static Bitmap ExtractImage(FileInfoEx entry, Size size, bool quality)
{
try
{
IntPtr iExtractImagePtr = IntPtr.Zero;
IExtractImage iExtractImage = null;
if (GetIExtractImage(entry, out iExtractImagePtr, out iExtractImage))
try
{
ShellDll.ShellAPI.SIZE prgSize = new ShellAPI.SIZE() { cx = size.Width, cy = size.Height };
IExtractImageFlags flags = IExtractImageFlags.Cache | IExtractImageFlags.Aspect;
if (quality) flags |= IExtractImageFlags.Quality;
StringBuilder location = new StringBuilder(260, 260);
try
{
int pdwPriority = 1;
iExtractImage.GetLocation(location,
location.Capacity, ref pdwPriority, ref prgSize, 32, ref flags);
}
catch (COMException) { }
IntPtr ptrBitmapImage = IntPtr.Zero;
iExtractImage.Extract(out ptrBitmapImage);
if (ptrBitmapImage != IntPtr.Zero)
return Bitmap.FromHbitmap(ptrBitmapImage);
}
catch (Exception) { }
finally
{
if (iExtractImage != null)
Marshal.ReleaseComObject(iExtractImage);
if (iExtractImagePtr != IntPtr.Zero)
Marshal.Release(iExtractImagePtr);
}
return null;
}
catch (NotSupportedException) { return null; }
}
private bool GetThumbnail(string file, IntPtr pidl, IShellFolder item)
{
IntPtr bmp = IntPtr.Zero;
IExtractImage extractImage = null;
try
{
string pidlPath = PathFromPidl(pidl);
if (Path.GetFileName(pidlPath).ToUpper().Equals(Path.GetFileName(file).ToUpper()))
{
// we have the item:
IUnknown iunk = null;
int prgf;
Guid iidExtractImage = new Guid("BB2E617C-0920-11d1-9A0B-00C04FC2D6C1");
item.GetUIObjectOf(IntPtr.Zero, 1, ref pidl, ref iidExtractImage, out prgf, ref iunk);
extractImage = (IExtractImage)iunk;
if (extractImage != null)
{
//Got an IExtractImage object!
ShellAPI.SIZE size = new ShellAPI.SIZE { cx = this.DesiredSize.Width, cy = this.DesiredSize.Height };
StringBuilder location = new StringBuilder(260, 260);
int priority = 0;
const int requestedColourDepth = 32;
const IEIFLAG flags = IEIFLAG.IEIFLAG_ASPECT | IEIFLAG.IEIFLAG_SCREEN;
int uFlags = (int)flags;
extractImage.GetLocation(location, location.Capacity, ref priority, ref size, requestedColourDepth, ref uFlags);
extractImage.Extract(out bmp);
if (bmp != IntPtr.Zero)
{
// create the image object:
this.ThumbNail = Image.FromHbitmap(bmp);
// is thumbNail owned by the Bitmap?
}
Marshal.ReleaseComObject(extractImage);
extractImage = null;
}
return true;
}
else
{
return false;
}
}
catch (Exception)
{
if (bmp != IntPtr.Zero)
{
UnManagedMethods.DeleteObject(bmp);
}
if (extractImage != null)
{
Marshal.ReleaseComObject(extractImage);
}
throw;
}
}
