//implementation of the singleton pattern
public static DBclass GetInstance()
{
if (instance == null)
{
instance = new DBclass();
}
return(instance);
}
public MainPage()
{
InitializeComponent();
this.clients = new List <Client>();
//instance of the DBhandler using singleton pattern
dbHandler = DBclass.GetInstance();
//loading DB
LoadDB();
//the index is initialized with the number of the clients in the list after the DB loading
this.index = clients.Count;
//when the application ends a method is called for saving the data in the DB
Application.ApplicationExit += new EventHandler(FinalSaveData);
}