如何删除最近的地图标记Google Map API

Question

I'm new to stackoverflow; noticed it was helpful for a lot of folks so I figured I'd try it out myself.

I'm working on a project now for Android.

The gist of it goes like this: the user spawns a map with markers generated at random from a set radius with the current location being the origin. The user then has to "collect" each of the virtual objects, at which point the game will end and go back to the main menu. Pretty simple concept.

My question: how do I remove markers based on the user's current location? In other words, how can I have the markers react to the user's location so that they're removed from the map respectively if the user is within a certain distance from them? I've looked online and found a few things on this site about calculating distance but nothing about removing markers based on distance.

Any help is appreciated. Also, critiques on my etiquette are accepted too; I'm unfamiliar with how one is to ask questions here.

Thanks.

Answer 1

You should provide what you have tried to ask for help. Have you achieved displaying markers on the map?

You need to register for location updates to make your app aware of the location changes. Details: http://developer.android.com/training/location/receive-location-updates.html

Each time a location update is provided, a method called onLocationChanged(Location userLocation) will be triggered. You should use this information for distance calculation.

Traverse your list of markers and check the distance for each of them.

Here is a method calculating the distance between two locations from a bird's eye:

public float getDistance(double startLat, double startLong, double goalLat, double goalLong)
{
    float[] resultArray = new float[1];
    Location.distanceBetween(startLat, startLong, goalLat, goalLong, resultArray);
    return resultArray[0];
}

Your marker object has a remove() method. Remove those that are closer to user's current location.