using PrecastConcretePlantListImplement.Models; namespace PrecastConcretePlantListImplement { public class DataListSingleton { private static DataListSingleton? _instance; public List Components { get; set; } public List Orders { get; set; } public List Reinforced { get; set; } private DataListSingleton() { Components = new List(); Orders = new List(); Reinforced = new List(); } public static DataListSingleton GetInstance() { if (_instance == null) { _instance = new DataListSingleton(); } return _instance; } } }