我正在创建一个简单的应用程序，它使用GPS获取纬度和经度值，我试图将其传递给谷歌地图以在地图上显示它。 GPS工作正常，但当我使用lat long的值时，它什么都不做。 使用默认标记只能看到地图。
MainActivity.java
public class MainActivity extends AppCompatActivity {
GoogleMap googleMap;
GpsTracker gps;
double lattitude;
double longitude;
Button btnMap;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnMap = (Button) findViewById(R.id.buttonMap);
gps = new GpsTracker(MainActivity.this);
if( gps.canGetLocation()) {
lattitude = gps.getLatitude();
longitude = gps.getLongitude();
Toast.makeText(getApplicationContext(),"Location"+lattitude+"/n"+longitude,Toast.LENGTH_SHORT).show();
} else {
gps.showAlertDialog();
}
try{
initialiseMap();
}catch( Exception e){
e.printStackTrace();
}
}
/**
* function to load map. If map is not created it will create it for you
* */
public void initialiseMap() {
if (googleMap == null) {
googleMap = ( (MapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();
Toast.makeText(getApplicationContext(),"Location"+lattitude+"/n"+longitude,Toast.LENGTH_SHORT).show();
MarkerOptions marker = new MarkerOptions().position(new LatLng(gps.getLatitude(),gps.getLongitude())).title("Location");
googleMap.addMarker(marker);
CameraPosition cameraPosition = new CameraPosition.Builder().target(new LatLng(lattitude,longitude)).zoom(12).build();
googleMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
Toast.makeText(getApplicationContext(),"Location"+lattitude+"/n"+longitude,Toast.LENGTH_SHORT).show();
// check if map is created successfully or not
if (googleMap == null) {
Toast.makeText(getApplicationContext(),
"Sorry! unable to create maps", Toast.LENGTH_SHORT)
.show();
}
}
}
@Override
protected void onPause() {
super.onPause();
}
@Override
protected void onResume() {
super.onResume();
}
@Override
protected void onStop() {
super.onStop();
gps.stopUsingGPS();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
}
显示lat很长。我已经读过我接收的lat long是双格式的，而谷歌地图的标记采用Double作为LatLng的参数。
GPSTracker.java
public class GpsTracker extends Service implements LocationListener {
private final Context mContext;
boolean isGPSEnabled = false;
boolean isNetworkEnabled = false;
boolean canGetLocation = false;
Location location;
double latitude;
double longitude;
private final long MIN_DISTANCE = 10;
private final long MIN_TIME = 30;
protected LocationManager locationManager;
public GpsTracker(Context context) {
this.mContext = context;
getLocation();
}
public Location getLocation() {
try {
locationManager = (LocationManager) mContext.getSystemService(LOCATION_SERVICE);
// getting GPS status
isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
// getting network status
isNetworkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!isGPSEnabled && !isNetworkEnabled) {
// no network provider enabled
} else {
this.canGetLocation = true;
// first get location from network provider
if (isNetworkEnabled) {
if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return null;
}
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, MIN_TIME, MIN_DISTANCE, this);
Log.d("Network", "Network");
if (locationManager != null) {
location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
// if GPS enabled get lat/long using GPS provider
if (isGPSEnabled) {
if (location == null) {
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, MIN_TIME, MIN_DISTANCE, this);
Log.d("GPS provider", "GPS provider");
if (locationManager != null) {
location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return location;
}
/* Stop using GPS listener
* calling this function will stop using GPS in your app*/
public void stopUsingGPS() {
if (locationManager != null) {
if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return;
}
locationManager.removeUpdates(GpsTracker.this);
}
}
// functions to get latitude and longitude
public double getLatitude()
{
if(location != null){
latitude = location.getLatitude();
}
return latitude;
}
public double getLongitude()
{
if(location != null){
longitude = location.getLongitude();
}
return longitude;
}
// function to check whether GPS/WiFi is enabled
public boolean canGetLocation()
{
return this.canGetLocation;
}
/* Function to show alert dialog
* on pressing settings button will launch settings options */
public void showAlertDialog()
{
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
alertDialog.setTitle("GPS Settings").setMessage("GPS not Enabled. /n Want to enable it ? ").setCancelable(false);
alertDialog.setPositiveButton("Settings", new OnClickListener() {
@Override
public void onClick(DialogInterface arg0, int arg1) {
// Implicit intent
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
}
});
alertDialog.setNegativeButton("No", new OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int arg1) {
dialog.cancel();
}
});
alertDialog.show();
}
@Override
public IBinder onBind(Intent arg0) {
// TODO Auto-generated method stub
return null;
}
@Override
public void onLocationChanged(Location arg0) {
// TODO Auto-generated method stub
}
@Override
public void onProviderDisabled(String arg0) {
// TODO Auto-generated method stub
}
@Override
public void onProviderEnabled(String arg0) {
// TODO Auto-generated method stub
}
@Override
public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
// TODO Auto-generated method stub
}
}
请告诉我现在还需要添加什么。也许覆盖方法？