Why does Hisense mobile phone lock the screen?

The reasons and solutions of Hisense mobile phone screen lock are as follows.

1, there are too many programs running in the background, which takes up too much running memory, resulting in suspended animation of the system.

2. The mobile phone stores too much information or installs too many programs.

3. Open the information and click the virtual menu button.

4. Click Settings-SMS Service Center in turn, and set the number of SMS Center as the number of the local network operator.