To cancel the lock sign in the upper right corner of Apple's mobile phone, just swipe the screen of the mobile phone from bottom to top in any interface, and the console will appear. There is a key exactly like that sign, which can be turned off by clicking it. :

iOS is a mobile operating system developed by Apple. Apple first announced this system at the Macworld conference on January 9, 27. It was originally designed for iPhone, and later it was applied to products such as iPod touch, iPad and Apple TV. IOS, like apple's Mac OS X operating system, belongs to a Unix-like commercial operating system. Originally, this system was called iPhone OS. Because iPad, iPhone and iPod touch all use iPhone OS, it was announced at the WWDC conference in 21 that it was renamed as iOS(iOS is a registered trademark of Cisco's network equipment operating system in the United States, and Apple's renaming has been authorized by Cisco).

in January p>216, with the release of version 9.2.1, Apple fixed a vulnerability that existed for three years. The vulnerability is that when an iPhone or iPad user accesses a network with a mandatory portal in a hotel or airport, the login page will display the terms of use of the network through an unencrypted HTTP connection. After the user accepts the terms, he can surf the Internet normally, but the embedded browser will share the unencrypted Cookie with Safari browser. Using this shared resource, hackers can create their own false forced portal and associate it with the WiFi network, thus stealing any unencrypted Cookie saved on the device.