如何停止追踪位置？

Question

I have a location-based alerting app when a user enters near to particular area, he/she should be alerted. I need to stop tracking location after the alert is clicked once. But my app is continuously alerting the user. How to stop it? I included code to check the distance between the user current location and destination in location onChange method.

public void onLocationChanged(Location location) {
  double lat1 = location.getLatitude();
  double lon1 = location.getLongitude();
  checkloc(lat1, lon1);
}

Answer 1

You might want to have a Flag, representing if the user was already warned, for instance:

boolean WAS_WAARNED = false;
void onLocationChanged(Location location) {
        if(!WAS_WARNED){
            WAS_WARNED = true;
            checkloc(location.getLatitude(), location.getLongitude());
        }
    }

Answer 2

You'll want to stop requesting location updates. This can be done by calling removeLocationUpdates on your location client.

For example:

alertButton.setOnClickListener(view -> {
            //Do some stuff.

            if (mLocationClient != null){
                mLocationClient.removeLocationUpdates(mLocationCallback)}
        });

Here, mLocationClient is your FusedLocationProviderClient, and mLocationCallback is your LocationCallback (this will have the onLocationChanged method within it). Since you check their location in the onLocationChanged method, there will no longer be updates to the location so the alert won't be created. You could also call removeLocationUpdates in your checkloc method if they are in the correct location.

Here is a link to the documentation for the FusedLocationProviderClient, giving more information.

Note: you may want to look up geofencing . It does something similar to what you want to do.

Answer 3

First Approach-> Save alert clicked the flag to PrefUtils which is the most useable memory for save status. When a user clicks the alert you just set the status true and save it to prefUtils.

public void onLocationChanged(Location location) {
    if(PrefUtils.getLoationStatus(getApplicationContext(), false)) {
        double lat1=location.getLatitude();
        double lon1=location.getLongitude();
        checkloc(lat1,lon1);
       PrefUtils.setLocationStatus(true);
    }
 }

Second Approach -> When the alert is clicked just set -> locationManager.removeUpdates(this);