Accessing another projects app.config properties?

Question

I have two projects within my solution, for this example I will call them project A and B.

Project B references A. Can Project B access the app.config properties of project A?

I wish to access an app key string within the app.config of A.

string tfsUri = ConfigurationManager.AppSettings["TfsUri"];

Answer 1

That's generally not a good idea, as you introduce hard dependencies between the projects. So if you can copy-paste config value, that will make your projects self-contained (however, this introduces duplication of config value).

You can also automate this, so that when you build a project the configuration dependency is automatically resolved.

Having-said this, there are other options, and in each case you may prefer to use something else. Your other options are:

• Use configuration transformation, like SlowCheetah
• Add whole config file from one project to another "as a link"
• Inject configuration value to your class (instead of reading it from config)
• Read other project's config file in runtime, by using things like ConfigurationManager.OpenExeConfiguration
• Also check out How to select different app.config for several build configurations

Answer 2

       var path = @"C:\Users\Stephen\source\repos\SensurityConfigurationTool\Configuration.UI\App.config";
        string directory = Path.GetDirectoryName(path);
        var pathRoot = Path.GetPathRoot(directory);
        string file = Path.GetFileName(path);


        ExeConfigurationFileMap fileMap = new ExeConfigurationFileMap
        {
            ExeConfigFilename = Path.Combine(Path.GetFullPath(directory + "\\" + file))
        };

        System.Configuration.Configuration config = ConfigurationManager.OpenMappedExeConfiguration(fileMap, ConfigurationUserLevel.None);

You basically get the relative path, then convert this to an absolute path