Update web config file in runtime in asp.net desktop application

Update web config file in runtime in asp.net desktop application .


 public static void updateConfigFile(string con)
        {
            try
            {
                var config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
                var connectionStringsSection = (ConnectionStringsSection)config.GetSection("connectionStrings");
                connectionStringsSection.ConnectionStrings["b02C_coreConnectionStrings"].ConnectionString = con;
                config.Save();
                ConfigurationManager.RefreshSection("connectionStrings");
            }
            catch (Exception E)
            {
                MessageBox.Show(E.ToString());
            }
        }