Setting up an ethernet connection for VNC (Pi B+)

I'm trying to set up VNC over an ethernet connection, using several tutorials I found online. I have an Ethernet cable running from my laptop to the pi, and I want to be able to control the pi via VNC from my laptop. I've enabled wifi sharing on my laptop, and I have the cable running, but the Pi isn't connected -- the up/down networking arrows are flashing. The frustrating thing is that it was working only an hour ago, and I was able to both ping google.com from the pi and connect to it via VNC. Now it is not connected to the Internet and I cannot connect to it by VNC. The only thing I did was set the pi to have a static local IP, and reboot it.