When an android alarm is triggered, press the power key to lock the screen. Two screen locks are played.

When an android alarm is triggered, press the power key to lock the screen. Two screen locks are played.
Two locks are triggered because Keyguard is locked when the screen is hidden, and then keyguard is automatically unlocked because FLAG_DISMISS_KEYGUARD windowsParam is set in alarm activity, this is the design of Google AOSP, and there will be two sides to the phone of Google AOSP, so the suggestions do not need to be modified.

Modify:
Alps \ frameworks \ base \ packages \ Keyguard \ src \ com \ android \ keyguard \ KeyguardViewMediator. java
# About 1384 rows:

MSuppressNextLockSound = false;

To:
If (authenticated ){
MSuppressNextLockSound = false;
} Else {
MSuppressNextLockSound = true;
}

It is also a non-user manual unlock situation, Suppress next Lock sound, no unlock sound.