Question

OK so we have something that is currently using OpenExeConfiguration for reading a config file, however this doesn’t work when running in the web context.

I’ve tried a variety of different ways of opening the web.config programmatically but I can’t seem to get it to read the correct web.config file. In case it matters I am currently debugging it in VS 2008.

1. config = System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration(System.Web.HttpContext.Current.Request.ApplicationPath);

2. config = ConfigurationManager.OpenMappedExeConfiguration(new ExeConfigurationFileMap { ExeConfigFilename = "web.config" }, ConfigurationUserLevel.None);

3. config = System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration("~");

4. config = System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration(null);

5.  System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration(System.Web.Hosting.HostingEnvironment.ApplicationVirtualPath);

It either opens up the wrong config file (either the machine config, or the VS /IDE/Web.config) or complains about the error:

{System.Configuration.ConfigurationErrorsException: An error occurred loading a configuration file: Failed to map the path ‘/’. —> System.InvalidOperationException: Failed to map the path ‘/’.

Edit –
OK so a combination of

config = System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration("~");

AND running Visual Studio 2008 As Administrator worked. Am hoping we don’t run into security/permission issues when we deploy to our web server / client environments!

Answer 1

So in the end I used this code (had to handle whether the web application was running, or if our unit test code was running).

System.Configuration.Configuration config = null;

if (System.Web.HttpContext.Current != null && !System.Web.HttpContext.Current.Request.PhysicalPath.Equals(string.Empty))
        config = System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration("~");
else
        config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);

Also have to be running Visual Studio in Administrator mode – which I found out you can set as a property on your shortcut so you don’t need to remember each time in Windows 7 to right click and run as administrator 🙂