Question

How can I setup support for per (roaming) user configuration settings for a particular plugin .DLL loaded from another application?

I have a .DLL that is loaded as add-in/plugin from another application, and want to persist configuration settings particular for this one independently of the main application that loads it, based on machine, .dll (=executable), roaming user or user profile.

I have found the System.Configuration.ExeConfigurationFileMap class that looks likely to provide what I need, but I can’t figure out how to setup the right paths specific for my (plugin) application.

What code I have so far is:

public class MyConfigurationSettings : ConfigurationSection
{
    public static MyConfigurationSettings GetSection (ConfigurationUserLevel ConfigLevel) 
    {
        string configFile = Assembly.GetAssembly(typeof(MyConfigurationSettings)).Location + ".config";
        ExeConfigurationFileMap configFileMap = new ExeConfigurationFileMap();
        configFileMap.ExeConfigFilename = configFile;
        configFileMap.LocalUserConfigFilename = <localUserConfigFile>; // ??? What filename to place here and how to get it based on the current environment ???
        configFileMap.RoamingUserConfigFilename = <roamingUserConfigFile>; // ???;

        System.Configuration.Configuration Config = ConfigurationManager.OpenMappedExeConfiguration(configFileMap, ConfigLevel);
        // ...
    }
}

Can anyone point me into the right direction? The available documentation and search results are too confusing or insufficient for me to get this right. Sorry , if this seems to be a silly question, but my C# (.NET) skills are going to get rusty after 4+ years not using it for earning daily bread.

I also believe it’s not primarily an issue about configuration settings management, but how to get paths for installation specific application instance configurations.

Answer 1

You set RoamingUserConfigFilename = RoamingName.config and put it under Roaming Profile:

%AppData%\[AppName]\[Vendor]\[CodedPath]\[Version]\RoamingName.config

Also you set LocalUserConfigFilename = LocalName.config and put it under Local Profile:

%LocalAppData%\[AppName]\[Vendor]\[CodedPath]\[Version]\LocalName.config

Now calling

ConfigurationManager.OpenMappedExeConfiguration(
    exeMap,
    ConfigurationUserLevel.PerUserRoamingAndLocal);

config will be read in the following order:

Source on MSDN blogs.

For samples search for User.config under c:\Users\[User]\AppData. Also see CP article.

Code Sample:

public static MyConfigurationSettings GetSection (ConfigurationUserLevel ConfigLevel) 
{
    try
    {
        string appDataPath = System.Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData);
        string localDataPath = System.Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
        System.Configuration.ExeConfigurationFileMap exeMap = new ExeConfigurationFileMap();
        exeMap.ExeConfigFilename = System.IO.Path.Combine(appDataPath, @"MyCompany\MyPlugin\Default.config");
        exeMap.RoamingUserConfigFilename = System.IO.Path.Combine(appDataPath, @"MyCompany\MyPlugin\Roaming.config");
        exeMap.LocalUserConfigFilename = System.IO.Path.Combine(localDataPath, @"MyCompany\MyPlugin\Local.config");

        System.Configuration.Configuration Config = ConfigurationManager.OpenMappedExeConfiguration(exeMap,ConfigLevel);

        return (MyConfigurationSettings)Config.GetSection("MyConfigurationSettings");

    }
    catch (Exception ex) {
        // ...
    }
    return null; // or throw an appropriate exception
}