Code Mode

public class FileInfoHelper {

    struct SHFILEINFO {

        public IntPtr hIcon;

        public int iIcon;

        public int dwAttributes;

        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260)]

        public string szDisplayName;

        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 80)]

        public string szTypeName;

    }

    [Flags]

    enum FileInfoFlags : int {

        SHGFI_ICON = 0x000000100,    // get icon

        SHGFI_DISPLAYNAME = 0x000000200,    // get display name

        SHGFI_TYPENAME = 0x000000400,    // get type name

        SHGFI_ATTRIBUTES = 0x000000800,    // get attributes

        SHGFI_ICONLOCATION = 0x000001000,    // get icon location

        SHGFI_EXETYPE = 0x000002000,    // return exe type

        SHGFI_SYSICONINDEX = 0x000004000,    // get system icon index

        SHGFI_LINKOVERLAY = 0x000008000,    // put a link overlay on icon

        SHGFI_SELECTED = 0x000010000,    // show icon in selected state

        SHGFI_ATTR_SPECIFIED = 0x000020000,    // get only specified attributes

        SHGFI_LARGEICON = 0x000000000,    // get large icon

        SHGFI_SMALLICON = 0x000000001,    // get small icon

        SHGFI_OPENICON = 0x000000002,    // get open icon

        SHGFI_SHELLICONSIZE = 0x000000004,    // get shell size icon

        SHGFI_PIDL = 0x000000008,    // pszPath is a pidl

        SHGFI_USEFILEATTRIBUTES = 0x000000010,    // use passed dwFileAttribute

        SHGFI_ADDOVERLAYS = 0x000000020,    // apply the appropriate overlays

        SHGFI_OVERLAYINDEX = 0x000000040,    // Get the index of the overlay in

        // the upper 8 bits of the iIcon

    }

    [DllImport("shell32.dll", CharSet = CharSet.Auto)]

    static extern Int64 SHGetFileInfo(string pszPath, int dwFileAttributes, out SHFILEINFO psfi, int cbFileInfo, FileInfoFlags uFlags);

    /// <summary>

    /// Creates a new bitmap with the small icon for a file.

    /// </summary>

    /// <param name="filename"></param>

    /// <returns></returns>

    public static Bitmap GetFileIconAsBitmap(string filename) {

        SHFILEINFO fi;

        SHGetFileInfo(filename, 0, out fi, Marshal.SizeOf(typeof(SHFILEINFO)), FileInfoFlags.SHGFI_ICON | FileInfoFlags.SHGFI_SMALLICON);

        using (Icon icon = Icon.FromHandle(fi.hIcon)) {

            Bitmap bm = new Bitmap(icon.Size.Width, icon.Size.Height);

            using (Graphics g = Graphics.FromImage(bm))

                g.DrawIcon(icon, 0, 0);

            return bm;

        }

    }

}