无法在Android智能手机上获得位置

Question

我正在尝试使用Wifi网络和GPS在我的Android智能手机（HTC Desire HD）上获取位置（纬度，经度）。

这是我使用的代码，只是我不断收到“位置不可用”

我正在使用Eclipse IDE。

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();
      }
} 

有人可以帮我这个吗？