我正在尝试使用用户gps位置来检测用户是否位于标记的半径.我有标记的坐标,但我不知道如何计算用户是否在该区域.我试图使用以下内容,但即使当前位置在圈子内,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();
}
}
解决方法
我刚刚运行更新的代码,并找出主要问题是什么.
您应该使用传入onMyLocationChange()回调的位置,以便它使用您当前的位置来判断设备是否在圆圈内：
googleMap.setOnMyLocationChangeListener(new GoogleMap.OnMyLocationChangeListener() {
@Override
public void onMyLocationChange(Location location) {
float[] distance = new float[2];
/*
Location.distanceBetween( mMarker.getPosition().latitude,distance);
*/
Location.distanceBetween( location.getLatitude(),location.getLongitude(),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,Toast.LENGTH_LONG).show();
}
}
});
以下是我运行的全部工作示例,它是您的原始代码的缩减版本：
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,distance);
*/
Location.distanceBetween( location.getLatitude(),distance);
if( distance[0] > mCircle.getRadius() ){
Toast.makeText(getBaseContext(),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(),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();
}
}
圈内结果：
圆圈外的结果：
