//保持屏幕常亮
PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
mWakeLock = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK | PowerManager.ACQUIRE_CAUSES_WAKEUP, LOCK_TAG);
mWakeLock.acquire();

//釋放屏幕常亮鎖
if(null != mWakeLock) {
    mWakeLock.release();
}

//屏幕解鎖
KeyguardManager keyguardManager = (KeyguardManager)getSystemService(KEYGUARD_SERVICE);
KeyguardLock keyguardLock = keyguardManager.newKeyguardLock(LOCK_TAG);
keyguardLock.disableKeyguard();
//屏幕鎖定
keyguardLock.reenableKeyguard();

<uses-permission android:name="android.permission.DISABLE_KEYGUARD" />
<uses-permission android:name="android.permission.WAKE_LOCK" />