(8)C#连sqlserver

            string str = ConfigurationManager.AppSettings["con_MES"];
            try
            {
                using (SqlConnection conn = new SqlConnection(str))
                {
                    conn.Open();
                    if (conn.State == ConnectionState.Open)
                    {
                        MessageBox.Show("连接成功");
                    }
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }