how to change, in CSS files, src attribute for images dynamically at deploy? (ASP.NET Web Forms)

I am creating an ASP.NET Web Forms website and I need to optimze the loading time of the website. One of the methods will be to make images load from dfferent servers.

For all i开发者_如何学Cmages exposed through aspx pages or user controls I use an utility that transforms the relative link of the resourses into an absolut one, linking to the preferred server resource.

I need to be able to do the same thing with images loaded from CSS files, meaning that for each image that is going to be loaded from the css file I need to change the src attribute to a prefered one. Do you know any tool that will do this, or any solution I can apply for my problem ???

There are a couple of options:

1. Transform the CSS files at build time and serve them as static files
2. Make the CSS files dynamic and let ASP.NET populate the paths to the images based on your existing setting

There are a number of ways of doing either of the above. Here are some links that might give you some ideas:

• Making Dynamic CSS content with ASP.NET
• LESS- The dynamic stylesheet language

Or you could even use ASP.NET Theming support to have two themes, one for development and one for production. Though I'm not sure that's a great option.