protected File(IFileAbstraction abstraction)
 {
     this.invariant_start_position = -1L;
     this.invariant_end_position = -1L;
     if (abstraction == null)
     {
         throw new ArgumentNullException("abstraction");
     }
     this.file_abstraction = abstraction;
 }

 public static TagLib.File Create(IFileAbstraction abstraction, string mimetype, ReadStyle propertiesStyle)
 {
     TagLib.File file3;
     if (mimetype == null)
     {
         string str = string.Empty;
         int startIndex = abstraction.Name.LastIndexOf(".") + 1;
         if ((startIndex >= 1) && (startIndex < abstraction.Name.Length))
         {
             str = abstraction.Name.Substring(startIndex, abstraction.Name.Length - startIndex);
         }
         mimetype = "taglib/" + str.ToLower(CultureInfo.InvariantCulture);
     }
     foreach (FileTypeResolver resolver in file_type_resolvers)
     {
         TagLib.File file = resolver(abstraction, mimetype, propertiesStyle);
         if (file != null)
         {
             return file;
         }
     }
     if (!FileTypes.AvailableTypes.ContainsKey(mimetype))
     {
         object[] args = new object[] { abstraction.Name, mimetype };
         throw new UnsupportedFormatException(string.Format(CultureInfo.InvariantCulture, "{0} ({1})", args));
     }
     Type type = FileTypes.AvailableTypes[mimetype];
     try
     {
         object[] objArray2 = new object[] { abstraction, propertiesStyle };
         TagLib.File file2 = (TagLib.File) Activator.CreateInstance(type, objArray2);
         file2.MimeType = mimetype;
         file3 = file2;
     }
     catch (TargetInvocationException exception)
     {
         throw exception.InnerException;
     }
     return file3;
 }

		/// <summary>
		///    Constructs and initializes a new instance of <see
		///    cref="File" /> for a specified file abstraction.
		/// </summary>
		/// <param name="abstraction">
		///    A <see cref="File.IFileAbstraction" /> object to use when
		///    reading from and writing to the file.
		/// </param>
		/// <exception cref="ArgumentNullException">
		///    <paramref name="abstraction" /> is <see langword="null"
		///    />.
		/// </exception>
		protected File (IFileAbstraction abstraction) : base (abstraction)
		{
		}

 /// <summary>
 ///    Constructs and initializes a new instance of <see
 ///    cref="File" /> for a specified file abstraction.
 /// </summary>
 /// <param name="abstraction">
 ///    A <see cref="IFileAbstraction" /> object to use when
 ///    reading from and writing to the file.
 /// </param>
 /// <exception cref="ArgumentNullException">
 ///    <paramref name="abstraction" /> is <see langword="null"
 ///    />.
 /// </exception>
 protected File(IFileAbstraction abstraction)
     : this(abstraction, ReadStyle.Average)
 {
 }

		/// <summary>
		///    Constructs and initializes a new instance of <see
		///    cref="File" /> for a specified file abstraction.
		/// </summary>
		/// <param name="abstraction">
		///    A <see cref="IFileAbstraction" /> object to use when
		///    reading from and writing to the file.
		/// </param>
		/// <exception cref="ArgumentNullException">
		///    <paramref name="abstraction" /> is <see langword="null"
		///    />.
		/// </exception>
		protected File (IFileAbstraction abstraction)
		{
			if (abstraction == null)
				throw new ArgumentNullException ("abstraction");
			
			file_abstraction = abstraction;
		}

		/// <summary>
		///    Creates a new instance of a <see cref="File" /> subclass
		///    for a specified file abstraction, mime-type, and read
		///    style.
		/// </summary>
		/// <param name="abstraction">
		///    A <see cref="IFileAbstraction" /> object to use when
		///    reading to and writing from the current instance.
		/// </param>
		/// <param name="mimetype">
		///    A <see cref="string" /> object containing the mime-type
		///    to use when selecting the appropriate class to use, or
		///    <see langword="null" /> if the extension in <paramref
		///    name="abstraction" /> is to be used.
		/// </param>
		/// <param name="propertiesStyle">
		///    A <see cref="ReadStyle" /> value specifying the level of
		///    detail to use when reading the media information from the
		///    new instance.
		/// </param>
		/// <returns>
		///    A new instance of <see cref="File" /> as read from the
		///    specified abstraction.
		/// </returns>
		/// <exception cref="CorruptFileException">
		///    The file could not be read due to corruption.
		/// </exception>
		/// <exception cref="UnsupportedFormatException">
		///    The file could not be read because the mime-type could
		///    not be resolved or the library does not support an
		///    internal feature of the file crucial to its reading.
		/// </exception>
		public static File Create (IFileAbstraction abstraction,
		                           string mimetype,
		                           ReadStyle propertiesStyle)
		{
			if(mimetype == null) {
				string ext = String.Empty;
				
				int index = abstraction.Name.LastIndexOf (".") + 1;
				
				if(index >= 1 && index < abstraction.Name.Length)
					ext = abstraction.Name.Substring (index,
						abstraction.Name.Length - index);
				
				mimetype = "taglib/" + ext.ToLower(
					CultureInfo.InvariantCulture);
			}
			
			foreach (FileTypeResolver resolver in file_type_resolvers) {
				File file = resolver(abstraction, mimetype,
					propertiesStyle);
				
				if(file != null)
					return file;
			}
			
			if (!FileTypes.AvailableTypes.ContainsKey(mimetype))
				throw new UnsupportedFormatException (
					String.Format (
						CultureInfo.InvariantCulture,
						"{0} ({1})",
						abstraction.Name,
						mimetype));
			
			Type file_type = FileTypes.AvailableTypes[mimetype];
			
			try {
				File file = (File) Activator.CreateInstance(
					file_type,
					new object [] {abstraction, propertiesStyle});
				
				file.MimeType = mimetype;
				return file;
			} catch (System.Reflection.TargetInvocationException e) {
				throw e.InnerException;
			}
		}

 /// <summary>
 ///    Constructs and initializes a new instance for a specified
 ///    file abstraction.
 /// </summary>
 /// <param name="abstraction">
 ///    A <see cref="File.IFileAbstraction" /> object to use when
 ///    reading from and writing to the file.
 /// </param>
 /// <exception cref="ArgumentNullException">
 ///    <paramref name="abstraction" /> is <see langword="null"
 ///    />.
 /// </exception>
 protected ImageBlockFile(IFileAbstraction abstraction)
     : base(abstraction)
 {
 }

 /// <summary>
 ///    Constructs and initializes a new instance of <see
 ///    cref="File" /> for a specified file abstraction.
 /// </summary>
 /// <param name="abstraction">
 ///    A <see cref="File.IFileAbstraction" /> object to use when
 ///    reading from and writing to the file.
 /// </param>
 /// <exception cref="ArgumentNullException">
 ///    <paramref name="abstraction" /> is <see langword="null"
 ///    />.
 /// </exception>
 protected BaseTiffFile(IFileAbstraction abstraction)
     : base(abstraction)
 {
     Magic = 42;
 }