我正在尝试在Google map 的左上角显示一个TextView
,以告知用户距特定标记点位置x距离的距离,即“您靠近位置A”,但仅在范围内显示TextView
。如果它们超出范围,则TextView
将消失。
我了解Google Places API会向您显示所有附近的位置,但是我只想显示用户在 map 上具有x距离的标记在附近的位置。
我怎样才能做到这一点?我仍然需要使用Google Places API吗?
我的类(class).java:
private GoogleMap mMap;
private LatLng currLocation;
private static final LatLng POINTA = new LatLng(32.820193, -117.232568);
private static final LatLng POINTB = new LatLng(32.829129, -117.232204);
private static final LatLng POINTC = new LatLng(32.821114, -117.231534);
private static final LatLng POINTD = new LatLng(32.825157, -117.232003);
// Array to store hotspot coordinates
private ArrayList<LatLng> markerCoords = new ArrayList<LatLng>();
private static final int POINTS = 4;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_map);
setUpMapIfNeeded();
}
@Override
public boolean onCreateOptionsMenu(Menu menu)
{
// Create MenuInflater object to insert ActionBar buttons
MenuInflater inflater = getMenuInflater();
// Display the ActionBar buttons from .xml
inflater.inflate(R.menu.menu_map, menu);
return true;
}
@Override
protected void onResume()
{
super.onResume();
setUpMapIfNeeded();
}
private void setUpMapIfNeeded()
{
if (mMap == null)
{
mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map))
.getMap();
// Check if we were successful in obtaining the map.
if (mMap != null)
{
markerCoords.add(POINTA);
markerCoords.add(POINTB);
markerCoords.add(POINTC);
markerCoords.add(POINTD);
setUpMap();
}
}
}
private void setUpMap()
{
// Set My Location blue dot
mMap.setMyLocationEnabled(true);
LocationManager locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
String provider = locationManager.getBestProvider(criteria, true);
Location myLocation = locationManager.getLastKnownLocation(provider);
if (myLocation != null)
{
double latitude = myLocation.getLatitude();
double longitude = myLocation.getLongitude();
currLocation = new LatLng(latitude, longitude);
}
for (int i = 0; i < POINTS; i++)
{
mMap.addMarker(new MarkerOptions()
.position(markerCoords.get(i))
.icon(BitmapDescriptorFactory.fromResource(R.drawable.post_it_marker)));
}
}
map.xml
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<fragment
xmlns:map="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/map"
android:name="com.google.android.gms.maps.SupportMapFragment"
map:cameraTargetLat="32.881416"
map:cameraTargetLng="-117.237428"
map:cameraZoom="15"
map:mapType="normal" />
</RelativeLayout>
有人可以指出我正确的方向吗?谢谢
最佳答案
简短答案location.distanceTo(anotherLocation)
我建议在setupMap中添加其他监听器,以一种简单的方式获取所有位置更改。
mMap.setMyLocationEnabled(true);
mMap.setOnMyLocationChangeListener(this);
然后,在此监听器中,您只需在当前位置和目标之间进行测量即可。距离(以米为单位)。
@Override
public void onMyLocationChange(Location location) {
Location target = new Location("target");
for(LatLng point : new LatLng[]{POINTA, POINTB, POINTC, POINTD}) {
target.setLatitude(point.latitude);
target.setLongitude(point.longitude);
if(location.distanceTo(target) < METERS_100) {
// bingo!
}
}
}
当然,您应该将自己的 Activity 设为
implements GoogleMap.OnMyLocationChangeListener
关于java - 如何不断从Google Maps Android中的当前位置检测附近的标记位置?,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/32284708/