Android GPS Proximity Alert when starting within the set proximity

问题

I would like to use Android's Proximity Alert for my garage door app. I have a button setup, that when pressed add's the proximity alert and starts tracking location. I want it to track indefinitely until I either enter or exit the proximity. If entering it will open the garage door, if exiting it will close the garage door after which I remove the proximity alert and GPS shuts off. I have it working close to perfectly.

The problem is, when I press the button while in my driveway, hence in the proximity, the intent always fires immediately with the extra KEY_PROXIMITY_ENTERING set to "entering". If I start the tracking outside of the proximity, it acts as expected, only fires once I enter the proximity. How can I get exiting the proximity when starting inside of it working in the same manner? Thanks in advance, here's my code.

In my activity:

float radius = 100f;
double lat = 37.422;
double lon = -122.084;

// Expiration is 10 Minutes
long expiration = 600000;

LocationManager locManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

Intent intent = new Intent(proximityIntentAction);

PendingIntent pendingIntent = PendingIntent.getBroadcast(getApplicationContext(), 1, intent, PendingIntent.FLAG_CANCEL_CURRENT);
locManager.addProximityAlert(lat, lon, radius, expiration, pendingIntent);

And here is my BroadcastReceiver:

public void onReceive(Context context, Intent intent)
{
    Log.v("SomeTag","Proximity Alert Intent Received");
    String direction = LocationManager.KEY_PROXIMITY_ENTERING;
    CharSequence text = direction;
    int duration = Toast.LENGTH_SHORT;

    Toast toast = Toast.makeText(context, "going: "+text, duration);
    toast.show();
    LocationManager locManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
    PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 1, intent, PendingIntent.FLAG_NO_CREATE);
    locManager.removeProximityAlert(pendingIntent);
}

回答1:

why not put a timer/delay on the firing of the button? For example, why not allow yourself a fixed amount of time to get out of the proximity before your app starts detecting? I think that many home alarms work in the same way. Or, another option might be to detect and ignore your first entry into the proximity and validate any subsequent re-entries to that proximity (i.e. your garage). What do you think?

来源：https://stackoverflow.com/questions/8556314/android-gps-proximity-alert-when-starting-within-the-set-proximity

标签

android

gps

locationmanager

proximity