' This function shows how to use the File property of the
' appSettings section.
' The File property is used to specify an auxiliary 
' configuration file.
' Usually you create an auxiliary file off-line to store 
' additional settings that you can modify as needed without
' causing an application restart,as in the case of a Web 
' application.
' These settings are then added to the ones defined in the
' application configuration file.
Private Shared Sub IntializeConfigurationFile()
    ' Create a set of unique key/value pairs to store in
    ' the appSettings section of an auxiliary configuration
    ' file.
    Dim time1 As String = String.Concat(Date.Now.ToLongDateString(), " ", Date.Now.ToLongTimeString())

    Dim time2 As String = String.Concat(Date.Now.ToLongDateString(), " ", New Date(2009, 6, 30).ToLongTimeString())

    Dim buffer() As String = {"<appSettings>", "<add key='AuxAppStg0' value='" & time1 & "'/>", "<add key='AuxAppStg1' value='" & time2 & "'/>", "</appSettings>"}

    ' Create an auxiliary configuration file and store the
    ' appSettings defined before.
    ' Note creating a file at run-time is just for demo 
    ' purposes to run this example.
    File.WriteAllLines("auxiliaryFile.config", buffer)

    ' Get the current configuration associated
    ' with the application.
    Dim config As System.Configuration.Configuration = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None)

    ' Associate the auxiliary with the default
    ' configuration file. 
    Dim appSettings As System.Configuration.AppSettingsSection = config.AppSettings
    appSettings.File = "auxiliaryFile.config"

    ' Save the configuration file.
    config.Save(ConfigurationSaveMode.Modified)

    ' Force a reload in memory of the 
    ' changed section.
    ConfigurationManager.RefreshSection("appSettings")

End Sub