Yes, you still have to do a build - but it's done automatically when you save (not an external build like an Ant build, but the "internal" build). If you didn't want to build on save, you'd uncheck the box. Having it build automatically makes some people nervous, I believe.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…