自动锁定屏幕
When you leave your computer, you should lock the screen to prevent other people from using your desktop and accessing your files. If you sometimes forget to lock your screen, you may wish to have your computer’s screen lock automatically after a set period of time. This will help to secure your computer when you aren’t using it.
当屏幕被锁定时，您的应用程序和系统进程将继续运行，但您需要再次输入密码才能继续使用它们。
设定几分钟后自动锁定屏幕。
Go to the Desktop and start typing Screen Lock.
Click on Screen Lock to open the panel.
Make sure Automatic Screen Lock is switched on, then select a length of time from the Automatic Screen Lock Delay drop-down list.
Applications can present notifications to you that are still displayed on your lock screen. This is convenient, for example, to see if you have any email without unlocking your screen. If you’re concerned about other people seeing these notifications, switch Show Notifications on Lock Screen off. For further notification settings, refer to Notifications and the notification list.
When your screen is locked, and you want to unlock it, press Esc, or swipe up from the bottom of the screen with your mouse. Then enter your password, and press Enter or click Unlock. Alternatively, just start typing your password and the lock curtain will be automatically raised as you type.