public List<UserInfo> GetUsers()
        {
            string tablename = "user";
            int numberOfUsers = 0;
            string str = "*";// "CardNo\tPin\tPassword\tGroup\tStartTime\tEndTime";
            int BUFFERSIZE = 1 * 1024 * 1024;
            byte[] buffer = new byte[BUFFERSIZE];
            string options = "";
            bool opt = false;
            List<UserInfo> AllUsers = new List<UserInfo>();

            if (IntPtr.Zero != h)
            {
                                //External Крашиться здесь
                numberOfUsers = GetDeviceData(h, ref buffer[0], BUFFERSIZE, devtablename, str, devdatfilter, options);
            }
            else
            {
                return AllUsers;
            }

            if (numberOfUsers >= 0)
            {
                AllUsers = GetUsersFromBuffer(buffer, numberOfUsers);
                return AllUsers;

            }
            else
            {
                PluginContext.Log.Error("Get data failed.The error is " + numberOfUsers);
                return AllUsers;
            }
        }