I use wlan to surf the Internet in a hotel teahouse. After a few hours, he sent me a text message saying that he owed dozens of dollars. Before I surf the Internet, I still have a phone bill of 100!

This is the case with Android phones. When surfing the Internet using WLAN or WIFI, GPRS will not be turned off by default. When you surf the Internet, the background software will not automatically enable the WLAN or WIFI you are connected to. If you still use GPRS, you will still be deducted. Alas, when I first started doing Android, I was fooled. Later, I downloaded a Haizhuo surfing. When I set up WLAN or WIFI to surf the Internet, I automatically turned off GPRS. When I'm not surfing the Internet, I can turn off GPRS with one click. I can also build a website that only supports GPRS, instead of. NET (My SIM card was set up n years ago, and I can surf the Internet with unlimited traffic every month).