//сериализира при затваряне на програмата
private void Form1_FormClosed(object sender, FormClosedEventArgs e)
{
//xml.Serialize<List<Product>>(productsList);
XmlService.Serialize <List <Product> >(XmlService.ListOfProducts);
}
//десериализира при зареждане на формата
private void Form1_FormLoad(object sender, EventArgs e)
{
//productsList = xml.Deserialize<List<Product>>();
XmlService.ListOfProducts = XmlService.Deserialize <List <Product> >();
AddProductsToPanel();
}