無法獲取當前位置Google地圖Android

Question

我知道這個問題與其他問題類似，但我無法理解在Google地圖中獲取我的位置的過程。我已經嘗試了很多教程，但我認爲我錯過了一些東西。

我用我的主類下面的代碼：

LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE); 
    Criteria criteria = new Criteria(); 
    //I am getting bestProvider = gps here 
    String bestProvider = locationManager.getBestProvider(criteria, true); 
    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) { 
     //getting location null here 
     Location location = locationManager.getLastKnownLocation(bestProvider); 

     if (location != null) { 
      onLocationChanged(location); 
     } 
     locationManager.requestLocationUpdates(bestProvider, 20000, 0, this); 
    }else 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)){ 
    //getting location null here 
     Location location = locationManager.getLastKnownLocation(bestProvider); 
     if (location != null) { 
      onLocationChanged(location); 
     } 
     locationManager.requestLocationUpdates(bestProvider, 20000, 0, this); 
    } 
} 

@Override 
public void onLocationChanged(Location location) { 
    TextView locationTv = (TextView) findViewById(R.id.latlongLocation); 
    double latitude = location.getLatitude(); 
    double longitude = location.getLongitude(); 
    LatLng latLng = new LatLng(latitude, longitude); 
    googleMap.addMarker(new MarkerOptions().position(latLng)); 
    googleMap.moveCamera(CameraUpdateFactory.newLatLng(latLng)); 
    googleMap.animateCamera(CameraUpdateFactory.zoomTo(15)); 
    locationTv.setText("Latitude:" + latitude + ", Longitude:" + longitude); 
} 

Answer 1

使用此代碼通過GPS提供商或網絡提供商處獲取當前位置

if (locationManager == null) { 
       locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE); 
      } 
      if (locationManager.getAllProviders().contains(LocationManager.GPS_PROVIDER)) { 
       isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER); 
       isNetworkProviderEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER); 
       if (isGPSEnabled) { 
        location = getLastLocationByProvider(locationManager, LocationManager.GPS_PROVIDER, getApplicationContext()); 
       } else if (isNetworkProviderEnabled) { 
        location = getLastLocationByProvider(locationManager, LocationManager.NETWORK_PROVIDER, getApplicationContext()); 
       } 
       if (location != null) { 
        latitude = location.getLatitude(); 
        longitude = location.getLongitude(); 
       } else { 
        if (isNetworkProviderEnabled) { 
         locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 100000, 1, this); 
         provider_info = LocationManager.NETWORK_PROVIDER; 
        } else if (isGPSEnabled) { 
         locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 100000, 1, this); 
         provider_info = LocationManager.GPS_PROVIDER; 
        } else { 

         alertDialog = Util.showOkDialog(new View.OnClickListener() { 
          @Override 
          public void onClick(View view) { 
           if (Env.currentActivity != null) { 
            if (Env.currentActivity instanceof LocationActivity) { 
             try { 
              gotoSettings(); 
             } catch (Exception e) { 
              e.printStackTrace(); 
             } 
            } 

           } 
           if (alertDialog != null) { 
            alertDialog.dismiss(); 
            alertDialog = null; 
           } 

          } 
         }, this.getResources().getString(R.string.location_service_validation)); 

        } 

        location = locationManager.getLastKnownLocation(provider_info); 
        if (location != null) { 
         latitude = location.getLatitude(); 
         longitude = location.getLongitude(); 
        } 
       } 

Answer 2

在這裏，您可以go.You請在您的應用程序中使用以下代碼示例：

public class CurrentLocation { 
Timer timer; 
LocationManager locationManager; 
LocationResult locationResult; 
boolean gpsEnabled=false; 
boolean networkEnabled=false; 

public boolean getLocation(Context context, LocationResult result) 
{ 
    //I use LocationResult callback class to pass location value from MyLocation to user code. 
    locationResult=result; 
    if(locationManager ==null) 
     locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE); 

    //exceptions will be thrown if provider is not permitted. 
    try{ 
     gpsEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);}catch(Exception ex){} 
    try{ 
     networkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);}catch(Exception ex){} 

    //don't start listeners if no provider is enabled 
    if(!gpsEnabled && !networkEnabled) 
     return false; 

    if(gpsEnabled) 
     locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListenerGps); 
    if(networkEnabled) 
     locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListenerNetwork); 
    timer =new Timer(); 
    timer.schedule(new GetLastLocation(), 20000); 
    return true; 
} 

LocationListener locationListenerGps = new LocationListener() { 
    public void onLocationChanged(Location location) { 
     timer.cancel(); 
     locationResult.gotLocation(location); 
     locationManager.removeUpdates(this); 
     locationManager.removeUpdates(locationListenerNetwork); 
    } 
    public void onProviderDisabled(String provider) {} 
    public void onProviderEnabled(String provider) {} 
    public void onStatusChanged(String provider, int status, Bundle extras) {} 
}; 

LocationListener locationListenerNetwork = new LocationListener() { 
    public void onLocationChanged(Location location) { 
     timer.cancel(); 
     locationResult.gotLocation(location); 
     locationManager.removeUpdates(this); 
     locationManager.removeUpdates(locationListenerGps); 
    } 
    public void onProviderDisabled(String provider) {} 
    public void onProviderEnabled(String provider) {} 
    public void onStatusChanged(String provider, int status, Bundle extras) {} 
}; 

class GetLastLocation extends TimerTask { 
    @Override 
    public void run() { 
     locationManager.removeUpdates(locationListenerGps); 
     locationManager.removeUpdates(locationListenerNetwork); 

     Location net_loc=null, gps_loc=null; 
     if(gpsEnabled) 
      gps_loc= locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER); 
     if(networkEnabled) 
      net_loc= locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER); 

     //if there are both values use the latest one 
     if(gps_loc!=null && net_loc!=null){ 
      if(gps_loc.getTime()>net_loc.getTime()) 
       locationResult.gotLocation(gps_loc); 
      else 
       locationResult.gotLocation(net_loc); 
      return; 
     } 

     if(gps_loc!=null){ 
      locationResult.gotLocation(gps_loc); 
      return; 
     } 
     if(net_loc!=null){ 
      locationResult.gotLocation(net_loc); 
      return; 
     } 
     locationResult.gotLocation(null); 
    } 
} 

}