android - Wi-Fi/モバイル ネットワークでは位置情報が正しく更新されませんが、GPS では更新されません

Question

以下は、他の作品から得たコーディングです。アプリに必要な変更を加えて、彼の作品の一部を実装しようとしています。ここでの問題は、[GET ADDRESS] ボタンをクリックしたときに適切なアドレスが返されないことです。また、wifi/モバイル ネットワークでのみ動作し、GPS では動作しません。その間、電話が連絡先にかけられているときに、データを自動投稿して切断する方法を知りたいです。ありがとうございました！

package com.yang.address;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;

import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import android.app.Activity;
import android.content.Context;
import android.location.Address;
import android.location.Geocoder;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class AddressActivity extends Activity {
    /** Called when the activity is first created. */
    Double lat, lon;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        Button btnLocation = (Button)findViewById(R.id.btnLocation);
        btnLocation.setOnClickListener(new OnClickListener() {
            public void onClick(View arg0) {
                // Acquire a reference to the system Location Manager
                LocationManager locationManager = (LocationManager) AddressActivity.this.getSystemService(Context.LOCATION_SERVICE);
                // Define a listener that responds to location updates
                LocationListener locationListener = new LocationListener() {
                    public void onLocationChanged(Location location) {
                        // Called when a new location is found by the network location provider.
                        lat = location.getLatitude();
                        lon = location.getLongitude();
                        TextView tv = (TextView) findViewById(R.id.txtLoc);
                        tv.setText("Your Location is:" + lat + "--" + lon);
                    }

                    public void onStatusChanged(String provider, int status, Bundle extras) {}
                    public void onProviderEnabled(String provider) {}
                    public void onProviderDisabled(String provider) {}
                };
                // Register the listener with the Location Manager to receive location updates
                locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);
            }
        });

        Button btnSend = (Button)findViewById(R.id.btnSend);
        btnSend.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                postData(lat, lon);
            }
        });

        Button btnAdd = (Button)findViewById(R.id.btnAddress);
        btnAdd.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                TextView tv = (TextView)findViewById(R.id.txtAddress);
                tv.setText(GetAddress(lat, lon));
            }
        });

    }

    public void postData(Double lat2, Double lon2) {
        // Create a new HttpClient and Post Header
        HttpClient httpclient = new DefaultHttpClient();
        HttpGet  htget = new HttpGet("http://myappurl.com/Home/Book/"+lat2+"/"+lon2);

        try {
            // Execute HTTP Post Request
            HttpResponse response = httpclient.execute(htget);
            String resp = response.getStatusLine().toString();
            Toast.makeText(this, resp, 5000).show();


        } catch (ClientProtocolException e) {
            Toast.makeText(this, "Error", 5000).show();
        } catch (IOException e) {
            Toast.makeText(this, "Error", 5000).show();
        }
    } 
    public String GetAddress(Double lat2, Double lon2)
    {
        Geocoder geocoder = new Geocoder(this, Locale.ENGLISH);
        String ret = "";
        try {
            List<Address> addresses = geocoder.getFromLocation(lat2,lon2, 1);
            if(addresses != null) {
                Address returnedAddress = addresses.get(0);
                StringBuilder strReturnedAddress = new StringBuilder("Address:\n");
                for(int i=0; i<returnedAddress.getMaxAddressLineIndex(); i++) {
                    strReturnedAddress.append(returnedAddress.getAddressLine(i)).append("\n");
                }
                ret = strReturnedAddress.toString();
            }
            else{
                ret = "No Address returned!";
            }
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            ret = "Can't get Address!";
        }
        return ret;
    }
}