I’ve carried a laptop into Shanghai probably 20 times by now. Never have they opened a single bag or even known I was carrying it. Only once has customs shown any interest in our baggage and that was long ago–I was wheeling out a cart piled with 4 suitcases (but no carryons) and there wasn’t anyone else going out at the time. Unusual–it drew the interest of a customs guy. The entry stamp two days earlier drew more interest. He started running the bags through his x-ray when my wife caught up (she was taking forever talking to the baggage people, I finally headed out to get her to quit talking) and explained we were picking up our bags the airline left behind and that was the end of it. (I left the explanation to her as she’s a native speaker.)
On the other hand 6 years ago she tripped a nuke scanner at customs and nobody showed up. We waited a bit and finally walked on out.
I have been to China in 2012 and arrived at Beijing Capital International Airport. I had a laptop and camera in my carry-on luggage, but my carry-on was not checked at all in China, it was only x-rayed in the country I flew from (Belgium).
Keep in mind that if you enter China in a different way (e.g by land) you might encounter a different situation. Here’s a forum post from 2007 where a guy claims he saw a Lonely Planet being confiscated at the border.
Credit:stackoverflow.com‘