如何在Android中启用接近传感器

Question

I have configured proximeter successfully in my code. Now I want to turn off & on screen programmatically. Code of sensor is working just fine and following method is also getting called.

@Override
public void onSensorChanged(SensorEvent event) {
    // TODO Auto-generated method stub

    PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
    WakeLock screenWakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK,"screenWakeLock");

    if (event.values[0] == 0) {
        screenWakeLock.acquire();
        Log.e("onSensorChanged","NEAR");
    } else {
        if (screenWakeLock != null) {
               if(screenWakeLock.isHeld())
                  screenWakeLock.release();
               screenWakeLock = null;
        }
        Log.e("onSensorChanged","FAR");  
    }
} 

My problem is that screen is not getting turn off. I also have added required permission in code. What else could be the reason ???

Answer 1

检查为此代码提交的更改， https://github.com/jitsi/jitsi-android/compare/6d356fa637ae...7aba481d773f

getPowerManager().newWakeLock( 32, "proximity_off");

Answer 2

As from my understanding wakelock is useful to keep screen on. I wasn't successful to turn screen on & off using it.

So, first I dimmed screen brightness as low as possible and then made all GUI elements unclickable. This way I solved my problem.

Following is method:

@Override
public void onSensorChanged(SensorEvent event) {
    // TODO Auto-generated method stub  
    WindowManager.LayoutParams params = this.getWindow().getAttributes();

    if (event.values[0] == 0) {
        //TODO Store original brightness value
        params.screenBrightness = 0.004f;
        this.getWindow().setAttributes(params);
        enableDisableViewGroup((ViewGroup)findViewById(R.id.YOUR_MAIN_LAYOUT).getParent(),false);
        Log.e("onSensorChanged","NEAR");

    } else {
        //TODO Store original brightness value          
        params.screenBrightness = -1.0f;
        this.getWindow().setAttributes(params);                     
        enableDisableViewGroup((ViewGroup)findViewById(R.id.YOUR_MAIN_LAYOUT).getParent(),true);
        Log.e("onSensorChanged","FAR");  
    }       
}  

From here , I took reference to disable touch for entire screen's view.

Answer 3

Try this shortcut:

PowerManager manager = getPowerManager();
WakeLock lock = manager.newWakeLock( 32, "proximity_off");
lock.acquire();

The above code doesn't even need the proximity sensor changed events to be listened. 32 is for a hidden WakeLock field that is used by the InCallActivity of the Phone and other such similar applications.