private void btn_save_Click(object sender, EventArgs e) { string userName = tb_userName.Text; string password = Crypting.EncryptSecret(tb_password.Text); Configuration configuration = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None); configuration.AppSettings.Settings["UserName"].Value = userName; configuration.AppSettings.Settings["Password"].Value = password; configuration.Save(ConfigurationSaveMode.Full, true); ConfigurationManager.RefreshSection("appSettings"); this.Close(); }