用户代码未处理ArgumentOutOfRangeException

Question

        private string shp_number()
        {
            SqlOperation sql = new SqlOperation();
            string str_sql = "select top 1 Shp_number from Fd_shopInformation_table order by Id desc";
            dt = sql.ExecuteDataSet(str_sql).Tables[0];
            if (dt.Rows.Count > 0)
            {
                string str_number = dt.Rows[0]["Shp_number"].ToString();
                int int_number = Convert.ToInt32(str_number.Substring(2, 9));
                int_number = int_number + 1;                string aa = "";
                for (int i = 0; i < (9 - int_number.ToString().Length); i++)
                {
                    aa = aa + "0";
                }
                string str_numbers = "TZ" + aa + int_number.ToString();                return str_numbers;
            }
            else
                return "TZ000000001";
        }

Answer 1

确保str_number有足够的长度用来截取str_number.Substring(2, 9)