How to lock Android screen via ADB?

Question

Is there a way to lock the Android screen via the ADB?

I find ways to lock the display in an apk, but I want to lock the screen from the PC via ADB, to simulate a displ

Answer 1

Here is a script to turn on/off the screen for every connected device including any pre-lollipop devices. I use this on my Jenkins server right before running any connected Android tests to make sure the devices are ready to go. Hope someone finds this useful!

#!/bin/sh

# Returns the power state of the screen 1 = on, 0 = off
getDisplayState() {
    state=$(adb -s $1 shell dumpsys power | grep mScreenOn= | grep -oE '(true|false)')

    # If we didn't get anything it might be a pre-lollipop device
    if [ "$state" = "" ]; then
        state=$(adb -s $1 shell dumpsys power | grep 'Display Power' | grep -oE '(ON|OFF)')
    fi

    if [ "$state" = "ON" ] || [ "$state" = "true" ]; then
        return 1;
    else
        return 0;
    fi
}

echo "Turning on screen on all connected devices..."

for device in `adb devices | grep device$ | cut -f1`
do
    echo -n "Found device: $device ... "

    getDisplayState $device
    state=$?

    # If the display is off, turn it on
    if [ $state -eq 0 ]; then
        echo "display was off, turning on"
        adb -s $device shell input keyevent 26
    else
        echo "display was on"
    fi

done