Updating .config file from an Custom Installer Class Action

Question

I\'ve tried updating my application\'s .config file during installer (via a .NET Installer Class Action). But, I can\'t seem to get ConfigurationManager to lis

Answer 1

You can access these settings using the System.Configuration namespace but, its not as simple as I would like and in retrospect using System.Xml.Linq is far simpler. Anyway, here is how I got it to work.

The important concept is, the applicationSettings section is not AppSettings, its a seperate section supported by the ClientSettingsSection type.

//Open the application level config file
ExeConfigurationFileMap exeMap = new ExeConfigurationFileMap();
exeMap.ExeConfigFilename = String.Format("{0}.config", 
    Context.Parameters["assemblypath"]);
Configuration config = ConfigurationManager.OpenMappedExeConfiguration(exeMap,
    ConfigurationUserLevel.None);

//Get the settings section
ClientSettingsSection settingsSection =
    config.GetSectionGroup("applicationSettings").Sections
         .OfType().Single();

//Update "TheSetting"
//I couldn't get the changes to persist unless
//I removed then readded the element.

SettingElement oldElement = settingsSection.Get("TheSetting");
settingsSection.Settings.Remove(oldElement);

SettingElement newElement = new SettingElement("TheSetting", 
    SettingSerializeAs.String);
newElement.Value = new SettingValueElement();
newElement.Value.ValueXml = oldElement.Value.ValueXml.CloneNode(true);
newElement.Value.ValueXml.InnerText = "Some New Value";
settingsSection.Add(newElement);

//Save the changes
config.Save(ConfigurationSaveMode.Full);

So, as you can see, simple. :-S