Programming ASP.NET, Second Edition

Configuring the Application

ASP.NET provides a very powerful and flexible means of configuring applications. This configuration is accomplished using text-based XML configuration files. The server-wide configuration file is called machine.config, described in Section 20-3.1. This is supplemented by a number of application-specific configuration files, all called web.config, located in the application virtual root directory and subdirectories.

This configuration scheme offers the following features:

• The XML files that control the configuration can be edited with any standard text editor or XML parser. It is not necessary to use the IIS control panel, as was the case with classic ASP.

• Since the configuration is accomplished with text files, it is easy to administer remotely. Files can be created or edited remotely, then copied into place via FTP or remote network access by anyone with suitable security clearance. There is no need for a person to be physically present at the server machine hosting the application in order to perform configuration chores, as is the case with classic ASP.

• The system is hierarchical. Each application inherits a baseline configuration from machine.config, located on the server. The web.config files then apply successive configuration attributes and parameters as the application directory tree structure is traversed. This will be explained in detail in Section 20-3.1.

• A corollary of the hierarchical nature of the system is that each application can have its ...