Common app.config between applications

Question

I have a need for a common config file shared by three applications

I solved it by adding in a file in appSettings

<appSettings file="ait.config">
    <!--<add key="Culture" value="zh-CN" />-->
    <add key="Culture" value=""/>
    <add key="ClientSettingsProvider.ServiceUri" value=""/>
</appSettings>

In the ait.config i store some common values like

<?xml version="1.0" encoding="utf-8" ?>
<appSettings>
    <add key="Username" value="Klabberius" />
</appSettings>

If i try to read it like

 string stvalue = ConfigurationManager.AppSettings["Username"];

It works fine , but if i try to write a value like

System.Configuration.Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);

config.AppSettings.Settings["Username"].Value = userName;
config.Save(ConfigurationSaveMode.Modified);
ConfigurationManager.RefreshSection("appSettings");

Instead of writing to the common file ait.config it add the key username to the standard app.config in each seperate application, anyone knows how to solve this.

Answer 1

With your method, you change the current config, not the file you want, because this is the document you opened. Unfortunately, the shared config seems not to be "accepted" as config file because it lacks the configuration node. You can open the shared config as a "normal" xml document from config (after your code line 1):

XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load(config.AppSettings.File);

Then you should just change the doc. Shame on me I am not good in linq to xml, the below works, but there is probably an easier way.

XmlNode n = xmlDoc.SelectSingleNode("//appSettings");
XmlNode x = n.ChildNodes[0];
x.Attributes[1].Value = userName;
xmlDoc.Save(config.AppSettings.File);