How do you handle multiple web.config files for multiple environments?

Question

The way I currently handle this is by having multiple config files such as:

web.config web.Prod.config web.QA.config web.Dev.config 

When the project gets deployed to the different environments I just rename the corresponding file with the correct settings.

Anyone have suggestions on how to handle this better?

EDIT: Here are some of the things that change in each config:

• WCF Client Endpoint urls and security
• Custom Database configs
• Session connection strings
• log4net settings

Answer 1

Scott Gu had an article on this once. The solution he presented was to use a Pre-build event to copy the correct config into place depending on the build configuration chosen.

I also noticed that there already is a similar question here on SO.

Answer 2

Transforms seem really helpful for this. You can replace certain sections with different rules.

http://msdn.microsoft.com/en-us/library/dd465318(v=vs.100).aspx