public System.Drawing.Bitmap GetThumbnail(string file, int width, int height)
{
if ((!File.Exists(file)) && (!Directory.Exists(file)))
{
throw new FileNotFoundException(
String.Format("The file '{0}' does not exist", file),
file);
}
if (thumbNail != null)
{
thumbNail.Dispose();
thumbNail = null;
}
IShellFolder folder = null;
try
{
folder = GetDesktopFolder;
}
catch (Exception ex)
{
throw ex;
}
if (folder != null)
{
IntPtr pidlMain = IntPtr.Zero;
try
{
int cParsed = 0;
int pdwAttrib = 0;
string filePath = Path.GetDirectoryName(file);
pidlMain = IntPtr.Zero;
folder.ParseDisplayName(
IntPtr.Zero,
IntPtr.Zero,
filePath,
out cParsed,
out pidlMain,
out pdwAttrib);
}
catch (Exception ex)
{
Marshal.ReleaseComObject(folder);
throw ex;
}
if (pidlMain != IntPtr.Zero)
{
// IShellFolder:
Guid iidShellFolder = new Guid("000214E6-0000-0000-C000-000000000046");
IShellFolder item = null;
try
{
folder.BindToObject(pidlMain, IntPtr.Zero, ref
iidShellFolder, ref item);
}
catch (Exception ex)
{
Marshal.ReleaseComObject(folder);
UnmanagedMethods.CoTaskMemFree(pidlMain);
throw ex;
}
if (item != null)
{
IEnumIDList idEnum = null;
try
{
item.EnumObjects(
IntPtr.Zero,
(ESHCONTF.SHCONTF_FOLDERS |
ESHCONTF.SHCONTF_NONFOLDERS),
ref idEnum);
}
catch (Exception ex)
{
Marshal.ReleaseComObject(folder);
UnmanagedMethods.CoTaskMemFree(pidlMain);
throw ex;
}
if (idEnum != null)
{
int hRes = 0;
IntPtr pidl = IntPtr.Zero;
int fetched = 0;
bool complete = false;
while (!complete)
{
hRes = idEnum.Next(1, ref pidl, out fetched);
if (hRes != 0)
{
pidl = IntPtr.Zero;
complete = true;
}
else
{
if (GetThumbnail(file, pidl, item, width, height))
{
complete = true;
}
}
if (pidl != IntPtr.Zero)
{
UnmanagedMethods.CoTaskMemFree(pidl);
}
}
Marshal.ReleaseComObject(idEnum);
}
Marshal.ReleaseComObject(item);
}
UnmanagedMethods.CoTaskMemFree(pidlMain);
}
Marshal.ReleaseComObject(folder);
}
return(thumbNail);
}