可以使用这个正则表达式：

  \bfoo\b。+ \bbar\b（？：$ | = [ ^ b 
现场演示： http://www.rubular.com/r/marUIfFzAz  
 
I want to match a URL containing both "foo" and "bar" but not "bar=0".

I'm trying to do this in Google Analytics and it doesn't support lookahead expressions.

So I am matching urls containing both "foo" and "bar" with this expression (foo.+bar) but how do I negate urls with "bar=0"?

You can use this regex:
\bfoo\b.+\bbar\b(?:$|=[^0]|[^=])




Live Demo: http://www.rubular.com/r/marUIfFzAz