C# DLL config file

Question

Im trying to add an app.config file to my DLL, but all attempts have failed.

According to MusicGenesis in \'Putting configuration information in a DLL\' this should

Answer 1

I had the same problem and searched the web for several hours but I couldn't find any solution so I made my own. I wondered why the .net configuration system is so inflexible.

Background: I want to have my DAL.dll to have its own config file for database and DAL settings. I also need the app.config for Enterprise Library and its own configurations. So I need both the app.config and dll.config.

What I did not wanted to do is pass-through every property/setting from the app to my DAL layer!

to bend the "AppDomain.CurrentDomain.SetupInformation.ConfigurationFile" is not possible because I need it for the normal app.config behavior.

My requirements/point of views were:

• NO manual copy of anything from ClassLibrary1.dll.config to WindowsFormsApplication1.exe.config because this is unreproducible for other developers.
• retain the usage of strong typing "Properties.Settings.Default.NameOfValue" (Settings behavior) because I think this is a major feature and I didn't want to lose it
• I found out the lack of ApplicationSettingsBase to inject your own/custom config file or management (all necessary fields are private in these classes)
• the usage of "configSource" file redirection is not possible because we would have to copy/rewrite the ClassLibrary1.dll.config and provide several XML files for several sections (I also didn't like this)
• I didn't like to write my own SettingsProvider for this simple task as MSDN suggests because I thought that simply would be too much
• I only need sections applicationSettings and connectionStrings from the config file

I came up with modifying the Settings.cs file and implemented a method that opens the ClassLibrary1.dll.config and reads the section information in a private field. After that, I've overriden "this[string propertyName]" so the generated Settings.Desginer.cs calls into my new Property instead of the base class. There the setting is read out of the List.

Finally there is the following code:

internal sealed partial class Settings
{
    private List list;

    /// 

    /// Initializes a new instance of the  class.
    /// 
    public Settings()
    {
        this.OpenAndStoreConfiguration();
    }

    /// 

    /// Opens the dll.config file and reads its sections into a private List of ConfigurationElement.
    /// 
    private void OpenAndStoreConfiguration()
    {
        string codebase = System.Reflection.Assembly.GetExecutingAssembly().CodeBase;
        Uri p = new Uri(codebase);
        string localPath = p.LocalPath;
        string executingFilename = System.IO.Path.GetFileNameWithoutExtension(localPath);
        string sectionGroupName = "applicationSettings";
        string sectionName = executingFilename + ".Properties.Settings";
        string configName = localPath + ".config";
        ExeConfigurationFileMap fileMap = new ExeConfigurationFileMap();
        fileMap.ExeConfigFilename = configName;
        Configuration config = ConfigurationManager.OpenMappedExeConfiguration(fileMap, ConfigurationUserLevel.None);

        // read section of properties
        var sectionGroup = config.GetSectionGroup(sectionGroupName);
        var settingsSection = (ClientSettingsSection)sectionGroup.Sections[sectionName];
        list = settingsSection.Settings.OfType().ToList();

        // read section of Connectionstrings
        var sections = config.Sections.OfType();
        var connSection = (from section in sections
                           where section.GetType() == typeof(ConnectionStringsSection)
                           select section).FirstOrDefault() as ConnectionStringsSection;
        if (connSection != null)
        {
            list.AddRange(connSection.ConnectionStrings.Cast());
        }
    }

    /// 

    /// Gets or sets the  with the specified property name.
    /// 
    /// 
    public override object this[string propertyName]
    {
        get
        {
            var result = (from item in list
                         where Convert.ToString(item.ElementInformation.Properties["name"].Value) == propertyName
                         select item).FirstOrDefault();
            if (result != null)
            {
                if (result.ElementInformation.Type == typeof(ConnectionStringSettings))
                {
                    return result.ElementInformation.Properties["connectionString"].Value;
                }
                else if (result.ElementInformation.Type == typeof(SettingElement))
                {
                    return result.ElementInformation.Properties["value"].Value;
                }
            }
            return null;
        }
        // ignore
        set
        {
            base[propertyName] = value;
        }
    }

You just will have to copy your ClassLibrary1.dll.config from the ClassLibrary1 output directory to your application's output directory. Perhaps someone will find it useful.