Multiple AppSettings files, is it possible?

52
votes

I want to create 3 AppSettings config files:

  • Database.config
  • Messages.config
  • Global.config

And after add in my App.config:

<appSettings file="Database.config" />
<appSettings file="Messages.config" />
<appSettings file="Global.config" />

But when I try to access a key that there is in one of three files with the ConfigurationManager, I got the following error:

Configuration system failed to initialize. Sections must only appear once per config file.

I cannot have more than one AppSettings config file?

2
c#.netconfigurationappsettings
Define different config sections, why you want add extra files? appconfig file is one for all of running projects root. – Saeed Amiri
Most readable to final user that 'll change some values. Only one file, i'll have a big file, and i don't want it. – Vinicius Ottoni
You could also use some xml file to do your configuration, but config file with 200-300 lines of code is not bad;) – Saeed Amiri
also see stackoverflow.com/questions/17575144/… – George Birbilis

2 Answers

56
votes

You can't have more than one appsettings because that's the name of a section. You can add a new section though that uses the same kind of section definition as appsettings. E.g.,

<configuration>
    <configSections>
        <section name="DatabaseConfig" type="System.Configuration.NameValueFileSectionHandler, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>
    </configSections>
    ....
    <DatabaseConfig>
       <add key="Whatever" value="stuff"/>
    </DatabaseConfig>
</configuration>
44
votes

Code for separate file:

Web.config:

<configSections>
    <section name="DatabaseConfig" type="System.Configuration.NameValueFileSectionHandler, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
    <section name="MessageConfig" type="System.Configuration.NameValueFileSectionHandler, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
    <section name="GlobalConfig" type="System.Configuration.NameValueFileSectionHandler, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
</configSections>

<DatabaseConfig configSource="database.config">
</DatabaseConfig>

<MessageConfig configSource="message.config">
</MessageConfig>

<GlobalConfig configSource="global.config">
</GlobalConfig>

database.config:

<DatabaseConfig>
  <add key="Name" value="ServerName" />
</DatabaseConfig>

etc...

Can be accessed via code like this:

var databaseConfiguration = (NameValueCollection)ConfigurationManager.GetSection("DatabaseConfig");
string name = databaseConfiguration["Name"];