Question

When developing a .NET Windows Forms Application we have the choice between those App.config tags to store our configuration values. Which one is better?

<configuration>    <!-- Choice 1 -->   <appSettings>     <add key='RequestTimeoutInMilliseconds' value='10000'/>   </appSettings>    <!-- Choice 2 -->   <configSections>     <sectionGroup name='applicationSettings' type='System.Configuration.ApplicationSettingsGroup, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c5612342342' >         <section name='Project1.Properties.Settings' type='System.Configuration.ClientSettingsSection, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c5612342342' requirePermission='false' />     </sectionGroup>   </configSections>   <applicationSettings>     <Project1.Properties.Settings>       <setting name='TABLEA' serializeAs='String'>         <value>TABLEA</value>       </setting>     </Project1.Properties.Settings>   </applicationSettings>  </configuration> 

Answer 1

The basic <appSettings> is easier to deal with – just slap in a <add key='....' value='...' /> entry and you’re done.

The downside is: there’s no type-checking, e.g. you cannot safely assume your number that you wanted to configure there really is a number – someone could put a string into that setting….. you just access it as ConfigurationManager['(key)'] and then it’s up to you to know what you’re dealing with.

Also, over time, the <appSettings> can get rather convoluted and messy, if lots of parts of your app start putting stuff in there (remember the old windows.ini file? :-)).

If you can, I would prefer and recommend using your own configuration sections – with .NET 2.0, it’s really become quite easy, That way, you can:

• a) Define your configuration settings in code and have them type-safe and checked
• b) You can cleanly separate YOUR settings from everyone else’s. And you can reuse your config code, too!

There’s a series of really good articles on you to demystify the .NET 2.0 configuration system on CodeProject:

1. Unraveling the mysteries of .NET 2.0 configuration

2. Decoding the mysteries of .NET 2.0 configuration

3. Cracking the mysteries of .NET 2.0 configuration

Highly recommended! Jon Rista did a great job explaining the configuration system in .NET 2.0.