android - Androidスマートフォンで場所を取得できません

Question

Wifi ネットワークと GPS を使用して、Android スマートフォン (HTC Desire HD) で場所 (緯度、経度) を取得しようとしています。

これは私が使用するコードですが、「場所が利用できません」というメッセージが表示され続けるだけです

私はEclipse IDEで作業しています。

import android.app.Activity;
import android.content.Context;
import android.location.Criteria;
import com.example.shortsproject.R;

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 LocationGetter extends Activity implements LocationListener {
    private TextView latituteField;
    private TextView longitudeField;
    private LocationManager locationManager;
    private String provider;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.location);
        latituteField = (TextView) findViewById(R.id.locationtext);
        longitudeField = (TextView) findViewById(R.id.locationtext2);

        // Get the location manager
        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
        // Define the criteria how to select the location 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();
      }
} 

誰かがこれで私を助けることができますか?