Navigation to external source files is available from text editor, Object Browser and Class View. When you want to navigate to the declaration of a library symbol, but you don't have library source code on your local machine, ReSharper retrieves the exact version of the file containing the declaration from the Source Server.
Select Options on the Tools menu. In the
Options dialog box, expand the Debugging
node and select Symbols. If you add a new symbol server or other location
to the list of locations, ReSharper will look for symbol files and download
them from the specified locations as well, for example, from the corporate symbol server. For more
Consider the following example: