The configuration API in .NET  gives us the ability to read and update configuration files, including web.config and machine.config files. You can read and write configuration files for your application, for another application on the same machine, or even an application on a different server. In this article, we will take a look at some of the highlights of the configuration API from the perspective of an ASP.NET developer, including how to use encryption and alternate configuration files.

The configuration API makes easy work of reading any setting in a configuration file using the GetSection static method. GetSection takes an XPath expression to indicate the section you want to get, and you can coerce the resulting object reference into a strongly typed reference for built-in section types.

There are a few caveats to updating configuration files. First, your application will need write permissions on the file. Typically, the NETWORK SERVICE and ASPNET accounts used by the runtime do not have write permissions on files and directories in an application’s home folder. One safe way to approach the problem is the technique used here - a combination of Windows authentication and impersonation. These settings allow the request to execute with the identity of the client. If the client has write permissions to the configuration file, the above snippet will be successful.


The Google APIs Client Library for .NET is generic .NET runtime client for Google Services. The library supports OAuth1.0a and OAuth2.0 authentication, and is able to generate strongly typed client libraries for Discovery-based services.