Sterling Knight

Sterling Sandmann Knight (born March 5, 1989) is an American actor, singer-songwriter, comedian and musician. He is best known for his roles in the 2009 film 17 Again as Alex, in Sonny With a Chance and So Random! as Chad Dylan Cooper, and in the Disney Channel Original Movie Starstruck as Christopher Wilde. He performed the title song from the movie StarStruck as Christopher Wilde (all the other songs were performed by Drew Ryan Scott as a vocal double).

source: Wikipedia