Android Google Map如何检查gps位置是否在圈内
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我正在尝试使用用户gps位置检测用户是否在标记的半径内。我有标记的坐标,但我不知道如何计算用户是否在该区域。我试过使用以下内容,但即使当前位置在圈内,我仍然会收到“外部”消息。
public class MapaEscola extends FragmentActivity {
private GoogleMap googleMap;
private Serializable escolas;
private ProgressDialog dialog;
private Circle mCircle;
private Marker mMarker;
@TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getActionBar().setDisplayHomeAsUpEnabled(true);
getActionBar().setHomeButtonEnabled(true);
setContentView(R.layout.maps);
// Loading map
initilizeMap();
// Changing map type
googleMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
// Showing / hiding your current location
googleMap.setMyLocationEnabled(true);
// Enable / Disable zooming controls
googleMap.getUiSettings().setZoomControlsEnabled(true);
// Enable / Disable my location button
googleMap.getUiSettings().setMyLocationButtonEnabled(true);
// Enable / Disable Compass icon
googleMap.getUiSettings().setCompassEnabled(true);
// Enable / Disable Rotate gesture
googleMap.getUiSettings().setRotateGesturesEnabled(true);
// Enable / Disable zooming functionality
googleMap.getUiSettings().setZoomGesturesEnabled(true);
Bundle extra = getIntent().getBundleExtra("extra");
ArrayList<Escolas> objects = (ArrayList<Escolas>) extra.getSerializable("array");
try {
for(int i = 0; i < objects.size(); i ++) {
System.out.println(" escolas " + objects.get(i).getLatitude() + " " + objects.get(i).getLongitude());
float latitude = objects.get(i).getLatitude();
float longitude = objects.get(i).getLongitude();
googleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(-23.316281, -51.155528), 15));
MarkerOptions options = new MarkerOptions();
// Setting the position of the marker
options.position(new LatLng(latitude, longitude));
googleMap = ((MapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();
LatLng latLng = new LatLng(latitude, longitude);
drawMarkerWithCircle(latLng);
googleMap.setOnMyLocationChangeListener(new GoogleMap.OnMyLocationChangeListener() {
@Override
public void onMyLocationChange(Location location) {
float[] distance = new float[2];
Location.distanceBetween( mMarker.getPosition().latitude, mMarker.getPosition().longitude,
mCircle.getCenter().latitude, mCircle.getCenter().longitude, distance);
if( distance[0] > (mCircle.getRadius() / 2) ){
Toast.makeText(getBaseContext(), "Outside", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(getBaseContext(), "Inside", Toast.LENGTH_LONG).show();
}
}
});
}
} catch (Exception e) {
e.printStackTrace();
}
}
private void drawMarkerWithCircle(LatLng position){
double radiusInMeters = 500.0;
int strokeColor = 0xffff0000; //red outline
int shadeColor = 0x44ff0000; //opaque red fill
CircleOptions circleOptions = new CircleOptions().center(position).radius(radiusInMeters).fillColor(shadeColor).strokeColor(strokeColor).strokeWidth(8);
mCircle = googleMap.addCircle(circleOptions);
MarkerOptions markerOptions = new MarkerOptions().position(position);
mMarker = googleMap.addMarker(markerOptions);
}
private void initilizeMap() {
if (googleMap == null) {
googleMap = ((MapFragment) getFragmentManager().findFragmentById(
R.id.map)).getMap();
// check if map is created successfully or not
if (googleMap == null) {
Toast.makeText(getApplicationContext(),
"Não foi possível carregar o mapa", Toast.LENGTH_SHORT)
.show();
}
}
}
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
@Override
public void onBackPressed() {
super.onBackPressed();
finish();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// TODO Auto-generated method stub
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu_main, menu);
return super.onCreateOptionsMenu(menu);
}
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
super.onBackPressed();
finish();
return true;
}
return true;
}
@Override
protected void onResume() {
super.onResume();
initilizeMap();
}
}
答案
我刚刚运行了更新的代码并找出了主要问题。
您应该使用传递给Location
回调的onMyLocationChange()
,以便它使用您当前的位置来判断设备是否在圈内:
googleMap.setOnMyLocationChangeListener(new GoogleMap.OnMyLocationChangeListener() {
@Override
public void onMyLocationChange(Location location) {
float[] distance = new float[2];
/*
Location.distanceBetween( mMarker.getPosition().latitude, mMarker.getPosition().longitude,
mCircle.getCenter().latitude, mCircle.getCenter().longitude, distance);
*/
Location.distanceBetween( location.getLatitude(), location.getLongitude(),
mCircle.getCenter().latitude, mCircle.getCenter().longitude, distance);
if( distance[0] > mCircle.getRadius() ){
Toast.makeText(getBaseContext(), "Outside, distance from center: " + distance[0] + " radius: " + mCircle.getRadius(), Toast.LENGTH_LONG).show();
} else {
Toast.makeText(getBaseContext(), "Inside, distance from center: " + distance[0] + " radius: " + mCircle.getRadius() , Toast.LENGTH_LONG).show();
}
}
});
这是我运行的完整工作示例,它是原始代码的简化版本:
public class MainActivity extends ActionBarActivity {
private GoogleMap googleMap;
private Serializable escolas;
private ProgressDialog dialog;
private Circle mCircle;
private Marker mMarker;
@TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setHomeButtonEnabled(true);
setContentView(R.layout.activity_main);
// Loading map
initilizeMap();
// Changing map type
googleMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
// Showing / hiding your current location
googleMap.setMyLocationEnabled(true);
// Enable / Disable zooming controls
googleMap.getUiSettings().setZoomControlsEnabled(true);
// Enable / Disable my location button
googleMap.getUiSettings().setMyLocationButtonEnabled(true);
// Enable / Disable Compass icon
googleMap.getUiSettings().setCompassEnabled(true);
// Enable / Disable Rotate gesture
googleMap.getUiSettings().setRotateGesturesEnabled(true);
// Enable / Disable zooming functionality
googleMap.getUiSettings().setZoomGesturesEnabled(true);
// Bundle extra = getIntent().getBundleExtra("extra");
//ArrayList<Escolas> objects = (ArrayList<Escolas>) extra.getSerializable("array");
try {
//test outside
double mLatitude = 37.77657;
double mLongitude = -122.417506;
//test inside
//double mLatitude = 37.7795516;
//double mLongitude = -122.39292;
googleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(mLatitude, mLongitude), 15));
MarkerOptions options = new MarkerOptions();
// Setting the position of the marker
options.position(new LatLng(mLatitude, mLongitude));
//googleMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap();
LatLng latLng = new LatLng(mLatitude, mLongitude);
drawMarkerWithCircle(latLng);
googleMap.setOnMyLocationChangeListener(new GoogleMap.OnMyLocationChangeListener() {
@Override
public void onMyLocationChange(Location location) {
float[] distance = new float[2];
/*
Location.distanceBetween( mMarker.getPosition().latitude, mMarker.getPosition().longitude,
mCircle.getCenter().latitude, mCircle.getCenter().longitude, distance);
*/
Location.distanceBetween( location.getLatitude(), location.getLongitude(),
mCircle.getCenter().latitude, mCircle.getCenter().longitude, distance);
if( distance[0] > mCircle.getRadius() ){
Toast.makeText(getBaseContext(), "Outside, distance from center: " + distance[0] + " radius: " + mCircle.getRadius(), Toast.LENGTH_LONG).show();
} else {
Toast.makeText(getBaseContext(), "Inside, distance from center: " + distance[0] + " radius: " + mCircle.getRadius() , Toast.LENGTH_LONG).show();
}
}
});
} catch (Exception e) {
e.printStackTrace();
}
}
private void drawMarkerWithCircle(LatLng position){
double radiusInMeters = 500.0;
int strokeColor = 0xffff0000; //red outline
int shadeColor = 0x44ff0000; //opaque red fill
CircleOptions circleOptions = new CircleOptions().center(position).radius(radiusInMeters).fillColor(shadeColor).strokeColor(strokeColor).strokeWidth(8);
mCircle = googleMap.addCircle(circleOptions);
MarkerOptions markerOptions = new MarkerOptions().position(position);
mMarker = googleMap.addMarker(markerOptions);
}
private void initilizeMap() {
if (googleMap == null) {
googleMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(
R.id.map)).getMap();
// check if map is created successfully or not
if (googleMap == null) {
Toast.makeText(getApplicationContext(),
"Não foi possível carregar o mapa", Toast.LENGTH_SHORT)
.show();
}
}
}
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
@Override
public void onBackPressed() {
super.onBackPressed();
finish();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// TODO Auto-generated method stub
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu_main, menu);
return super.onCreateOptionsMenu(menu);
}
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
super.onBackPressed();
finish();
return true;
}
return true;
}
@Override
protected void onResume() {
super.onResume();
initilizeMap();
}
}
圈内的结果:
圈外的结果:
另一答案
@Daniel Nugent:imho getRadius()
将返回半径而不是直径所以“/2
”是错误的
@WARpoluido:我看不到位置变化时更新mMarker
变量。你为什么不使用给onMyLocationChange()
的价值?
Location.distanceBetween( mCircle.getCenter().latitude, mCircle.getCenter().longitude, location.getLatitude(), location.getLongitude(), distance);
if( distance[0] > mCircle.getRadius() ){
...
另一答案
嗨,我已经使用此代码正常工作了
//Getting current location
private void getCurrentLocation() {
mMap.clear();
//Creating a location object
Location location = LocationServices.FusedLocationApi.getLastLocation(googleApiClient);
if (location != null) {
//Getting longitude and latitude
longitude = location.getLongitude();
latitude = location.getLatitude();
//moving the map to location
moveMap();
}
Circle circle = mMap.add以上是关于Android Google Map如何检查gps位置是否在圈内的主要内容,如果未能解决你的问题,请参考以下文章
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