DarthPedro: Random Thoughts

using System;

using System.IO;

using System.Xml;

using System.Xml.Serialization;



namespace MyClassLibrary

{

    /// <summary>

    /// XmlPersistedClass allows derieved classes to provide Save/Load functionality

    /// to and from xml files.  The methods are generic and can be overridden or 

    /// overloaded to provide type specific versions. 

    /// </summary>

    [Serializable]

    public abstract class XmlPersistedClass

    {

        /// <summary>

        /// Default constructor -- required for serialization.

        /// </summary>

        public XmlPersistedClass()

        {

        }



        /// <summary>

        /// Saves this class to xml at the specified filename.

        /// </summary>

        /// <param name="pathFilename">Filename by which to save the class.</param>

        /// <param name="classType">The type of the class to save.</param>

        virtual public void Save(string pathFilename, Type classType)

        {

            // make sure the string and type are valid.

            if (pathFilename == null || classType == null)

                throw new ArgumentNullException();

            if (pathFilename.Length < 1)

                throw new ArgumentException();



            // Create an instance of the XmlSerializer class; specify the type of object to serialize.

            XmlSerializer serializer = new XmlSerializer(classType);

            TextWriter writer = new StreamWriter(pathFilename);



            // Serialize this object, and close the TextWriter.

            serializer.Serialize(writer, this);

            writer.Close();

        }



        /// <summary>

        /// Loads a class from xml at the specified filename.

        /// </summary>

        /// <param name="pathFilename">Filename from which to load the class</param>

        /// <param name="classType">The expected type of the class to load.</param>

        /// <returns>Returns the class with data loaded from the file.</returns>

        static public object Load(string pathFilename, Type classType)

        {

            // make sure the string and type are valid.

            if (pathFilename == null || classType == null)

                throw new ArgumentNullException();

            if (pathFilename.Length < 1)

                throw new ArgumentException();



            FileStream stream = null;

            try    

            {

                // Create an instance of the XmlSerializer class; 

                specify the type of object to be deserialized.

                XmlSerializer serializer = new XmlSerializer(classType);



                // A FileStream is needed to read the XML document.

                stream = new FileStream(pathFilename, FileMode.Open);

                // Use the Deserialize method to restore the object's state with data from the XML document.

                object objLoaded = serializer.Deserialize(stream);

                stream.Close();

                return objLoaded;

            }

            catch (FileNotFoundException)

            {

                // do nothing, but return null...

                return null;

            }

            finally

            {

                if (stream != null)

                {

                    stream.Close();

                }

            }

        }

    }

}

    /// <summary>

    /// Class that derives from XmlPersistedClass and adds properties to be

    /// persisted. Then adds type-specific Load and Save methods.

    /// </summary>

    public class MyTestClass : XmlPersistedClass

    {

        // private members

        private int number = 0;

        private ArrayList list = new ArrayList();



        // public properties

        [XmlAttribute] public int Number

        {

            get { return number; }

            set { number = value; }

        }



        [XmlArray] public ArrayList List

        {

            get { return list; }

            set { list = value; }

        }

        /// <summary>

        /// Default constructor - required for serialization.

        /// </summary>

        public MyTestClass()

        {

        }



        /// <summary>

        /// Saves this class to the specified file.

        /// </summary>

        /// <param name="fileName">Full path to file.</param>

        public virtual void Save(string fileName)

        {

            base.Save(fileName, typeof(MyTestClass));

        }



        /// <summary>

        /// Loads a new instance of this class from the specified file.

        /// </summary>

        /// <param name="fileName">Full path to file.</param>

        public static MyTestClass Load(string fileName)

        {

            return (MyTestClass)XmlPersistedClass.Load(fileName, typeof(MyTestClass));

        }

    }