Changing App.config at Runtime

Question

I\'m writing a test WinForms / C# / .NET 3.5 application for the system we\'re developing and we fell in the need to switch between .config files at runtime, but this is tur

Answer 1

UPDATE

The solution below did not work because XmlDocument does not dispose and it seems some versions of .net do not close correctly when given a file path. The solution (example code in the link) is to open a stream which will do a dispose and pass that stream to the save function.

A solution is shown here. http://web-beta.archive.org/web/20150107004558/www.devnewsgroups.net/group/microsoft.public.dotnet.xml/topic40736.aspx

---

Old stuff below

Try this:

Note, I changed to xpath, but it has been a while so I might have gotten the xpath wrong, but in any case you should use xpath and not walk the tree. As you can see it is much clearer.

The important point is the using statement which will dispose(), which I think was your problem.

Let me know, good luck.

  public void UpdateAppSettings(string key, string value)
  {
    using (XmlDocument xmlDoc = new XmlDocument())
    {
      xmlDoc.Load(AppDomain.CurrentDomain.SetupInformation.ConfigurationFile);
      xmlDoc.DocumentElement.FirstChild.SelectSingleNode("descendant::"+key).Attributes[0].Value = value;
      xmlDoc.Save(AppDomain.CurrentDomain.SetupInformation.ConfigurationFile);
    }
    System.Configuration.ConfigurationManager.RefreshSection("section/subSection");
  }