質問

My app doesnt want to use GPS and using network to get location instead. I checked that by analysing latitude and longtitude, they're a little bit random (like network location).

If I use another app using GPS (e.g Endomondo Sports tracker) I see characteristic mark, which means, that GPS is currently working:

enter image description here

When I launch my application, there's no mark at all.

I'm using following code (code by Lars Vogella, Source: http://www.vogella.com/articles/AndroidLocationAPI/article.html):

import android.app.Activity;
import android.content.Context;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.widget.TextView;
import android.widget.Toast;

public class ShowLocationActivity extends Activity implements LocationListener {
  private TextView latituteField;
  private TextView longitudeField;
  private LocationManager locationManager;
  private String provider;


/** Called when the activity is first created. */

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    latituteField = (TextView) findViewById(R.id.TextView02);
    longitudeField = (TextView) findViewById(R.id.TextView04);

    // Get the location manager
    locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    // Define the criteria how to select the locatioin provider -> use
    // default
    Criteria criteria = new Criteria();
    provider = locationManager.getBestProvider(criteria, false);
    Location location = locationManager.getLastKnownLocation(provider);

    // Initialize the location fields
    if (location != null) {
      System.out.println("Provider " + provider + " has been selected.");
      onLocationChanged(location);
    } else {
      latituteField.setText("Location not available");
      longitudeField.setText("Location not available");
    }
  }

  /* Request updates at startup */
  @Override
  protected void onResume() {
    super.onResume();
    locationManager.requestLocationUpdates(provider, 400, 1, this);
  }

  /* Remove the locationlistener updates when Activity is paused */
  @Override
  protected void onPause() {
    super.onPause();
    locationManager.removeUpdates(this);
  }

  @Override
  public void onLocationChanged(Location location) {
    int lat = (int) (location.getLatitude());
    int lng = (int) (location.getLongitude());
    latituteField.setText(String.valueOf(lat));
    longitudeField.setText(String.valueOf(lng));
  }

  @Override
  public void onStatusChanged(String provider, int status, Bundle extras) {
    // TODO Auto-generated method stub

  }

  @Override
  public void onProviderEnabled(String provider) {
    Toast.makeText(this, "Enabled new provider " + provider,
        Toast.LENGTH_SHORT).show();

  }

  @Override
  public void onProviderDisabled(String provider) {
    Toast.makeText(this, "Disabled provider " + provider,
        Toast.LENGTH_SHORT).show();
  }
} 

Of course I added permissions in AndroidManifest.xml file:

<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET" />

Any ideas?

役に立ちましたか?

解決

Solution: you can use GPS instead of selecting best provider by deciding criteria.

Example, Replace:

locationManager.requestLocationUpdates(provider, 400, 1, this);

With:

locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 400, 1, this);

Explaination:

Depending on your application's use case, you have to choose a specific location provider i.e. LocationManager.GPS_PROVIDER or LocationManager.NETWORK_PROVIDER

Alternatively, you can provide some input criteria such as accuracy, power requirement, monetary cost, and so on, and let Android decide a closest match location provider

    // Retrieve a list of location providers that have fine accuracy, no monetary cost, etc
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);
criteria.setCostAllowed(false);
String providerName = locManager.getBestProvider(criteria, true);
//and then you can make location update request with selected best provider
locationManager.requestLocationUpdates(provider, 400, 1, this); 

Have a look at how to use locationmanager , how to specify Criteria and how getBestProvider method works for reference

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