1#region Singleton   ...
2
3        private static ContactListData instance;
4        private static int numOfReference;
5
6        private ContactListData()
7        {
8            numOfReference = 0;
9        }
10        public static ContactListData GetInstance()
11        {
12            if (instance == null)
13            {
14                instance = new ContactListData();
15            }
16            numOfReference++;
17            return instance;
18        }
19        public static int Reference
20        {
21            get { return numOfReference; }
22        }
23        #endregion