在锁定屏幕上按开/关开关时是否有一个空白屏幕？ -- settings 领域 和 lock-screens 领域 和 power-on 领域 android 相关 的问题

I think you are trying to disable double tap to open...? You can disable it in Gestures/Moves in the settings    Natsu Kage    2020-01-27 05:13:31Z, License: CC BY-SA 4.0

No, Double tap is resolved. The Accessibility problem arose because I put my hand in the laptop bag in the front pocket (where stuff is kept) and touched the finger scanner. Because the screen remains active during lockscreen, it switched on and then (as chance happens) bounced about unseen until it hit talkbalk. I've had every iteration of android since that first Motorola (remember that one? with the sliding keyboard?) and the most recent was the Nexus 5X. All of them blanked the screen when the off button was depressed. Problem is as stated    ilinkcs    2020-01-27 06:27:31Z, License: CC BY-SA 4.0

This issue pre-dates the TalkBack. Having an 'active' screen means that whenever the phone is bumped (in the pocket, laptop bag etc) it momentarily responds with an unlock screen, this drains battery, and can't be good for the phone. The inadvertant finger scan is an escalation of all this, of course    ilinkcs    2020-01-27 06:59:45Z, License: CC BY-SA 4.0

Resolved after a factory reinstall    ilinkcs    2020-02-09 19:34:41Z, License: CC BY-SA 4.0