Use BinaryFormatter to serialize user defined class : Binary Formatter « File Directory Stream « C# / CSharp Tutorial

1. C# / CSharp Tutorial
2. File Directory Stream
3. Binary Formatter

using System;

using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;

[Serializable]
public class Product {
    public long Id;
    public string Name;
    public double Price;

    [NonSerialized]
    string Notes;

    public Product(long id, string name, double price, string notes) {
        Id = id;
        Name = name;
        Price = price;
        Notes = notes;
    }

    public override string ToString() {
        return string.Format("{0}: {1} (${2:F2}) {3}", Id, Name, Price, Notes);
    }
}
class Program {
    static void Main(string[] args) {
            List<Product> products = new List<Product>();
            products.Add(new Product(1, "A", 1000.0, "s"));
            products.Add(new Product(2, "B", 25.0, "T"));
            products.Add(new Product(4, "C", 12.0, "k"));

            foreach (Product product in products) {
                Console.WriteLine(product);
            }
            IFormatter serializer = new BinaryFormatter();
            FileStream saveFile = new FileStream("Products.bin", FileMode.Create, FileAccess.Write);
            serializer.Serialize(saveFile, products);
            saveFile.Close();

            FileStream loadFile =new FileStream("Products.bin", FileMode.Open, FileAccess.Read);
            List<Product> savedProducts = serializer.Deserialize(loadFile) as List<Product>;
            loadFile.Close();
            foreach (Product product in savedProducts) {
                Console.WriteLine(product);
            }
    }

}