public bool UpdateAt(PurchaseHistory UpdElement, int ElementIndex)
{
ListOfHistory[ElementIndex] = UpdElement;
return(true);
}
public bool Remove(PurchaseHistory DelElement)
{
try { ListOfHistory.Remove(DelElement); }
catch (Exception) { return(false); }
return(true);
}
public int Add(PurchaseHistory NewElement)
{
ListOfHistory.Add(NewElement);
return(0);
}