Question

I’m attempting to update some values in the web.config file from code during an install process.

So far I’ve found this for updating the connection string,

    ' Open Application's Web.Config
    Dim config = WebConfigurationManager.OpenWebConfiguration("/" + TargetVDir, friendlySiteName)

    'Add new connection string setting for web.config
    Dim appDatabase = New ConnectionStringSettings()
    appDatabase.Name = "TimeOffEntities"
    appDatabase.ConnectionString = EFconnectionstring

    config.ConnectionStrings.ConnectionStrings.Clear()
    config.ConnectionStrings.ConnectionStrings.Add(appDatabase)

    ' Persist web.config settings
    config.Save()

However I need to update another section and I’m not sure how. I have the settings for an email and I’m not sure how to update them. Relevant web.config section below,

<configuration>

  <system.net>
    <mailSettings>
      <smtp>
        <network 
             host="relayServerHostname" 
             port="portNumber"
             userName="username"
             password="password" />
      </smtp>
    </mailSettings>
  </system.net>

</configuration>

Answer 1

You can do it as follows:

Configuration config = WebConfigurationManager.OpenWebConfiguration(...);

ConfigurationSection section = config.GetSection("system.net/mailSettings/smtp");
System.Net.Configuration.SmtpSection smtpSection = section as
                      System.Net.Configuration.SmtpSection;
if (smtpSection != null)
{
    smtpSection.Network.Host = ...;
}
config.Save();

And of course similarly for other configuration sections.

If you click on “More…” in the Inheritance Hierarchy section of the MSDN documentation for the ConfigurationSection class you’ll get a list of the ConfigurationSection-derived types for all the standard configuration sections.