The most effective way to find people in Shanghai is as follows: The first thing to do is to call the police. First, the police file an investigation, so that they can get some information and clues, because people nowadays can't travel without ID cards and various communication tools. What the police can help is to query personal big data. Then, release "Looking for You" through the network platform. There are two kinds of publishing through the network. One is to post in various online forums to find relatives, and the other is to post in various free tracing websites and anti-MLM websites to find relatives. The third is to offer a reward, which requires a professional tracing team to be entrusted in good faith.
If you have a mobile phone, you can locate the lost person through it. Nowadays, most smart phones have location function (looking for mobile phones). Known mobile phones of Huawei, Glory, Xiaomi, Meizu, Apple and other brands all have their own means, or locate lost people through cars. In addition, some smart car products also have positioning function, and we can find the lost people in these two ways. But in terms of accuracy, this scheme is not as accurate as the previous mobile phone positioning.