react-router provides two props for setting a specific style on a Link component whose path matches our current route. activeStyle allows for an inline style while activeClassName allows for an class defined in an external stylesheet.
const Links = () => <nav > <Link activeStyle={{color: ‘green‘}} to="/">Home</Link> <Link activeStyle={{color: ‘green‘}} to="/about">About</Link> <Link activeClassName="active" to="/contact">Contact</Link> </nav>;
.active{ color: green; }
[React] React Router: activeStyle & activeClassName
原文：http://www.cnblogs.com/Answer1215/p/5327591.html