反向地理编码停止工作

Question

我有一个应用程序应该通过按下按钮从纬度和经度中找到地址名称。我一直在使用反向地理编码，直到几天我才尝试添加其他按钮。从那以后，每次调试代码时，它都会跳过地址行并退出方法。我无法弄清楚代码在以前工作正常时出了什么问题。

这是我一直在使用的代码

   public class MainActivity extends Activity implements LocationListener{

    protected LocationManager locationManager;
    protected LocationListener locationListener;
    protected Context context;
    //declaration of variables for latitude and longitude
    TextView txtLat;
    TextView txtLon;
    String lat;
    String provider;
    protected String latitude,longitude;
    protected boolean gps_enabled, network_enabled;
    private static final long time_bw_up_min = 50*60;
    double latitudedouble;
    double longitudedouble;
    List<AddressList> addressList;

    private static final long dist_change_update_min = 10;

    public MainActivity() {
        this.addressList = null;
    }

    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        //initialize the text displays showing latitude and longitude
        txtLat = (TextView) findViewById(R.id.latitude);
        txtLon = (TextView) findViewById(R.id.longitude);

        //run the method to access the devices location
        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,time_bw_up_min,dist_change_update_min, this);
    }

     public void goButtonClicked(View v) {

        Geocoder geocoder = new Geocoder(this, Locale.ENGLISH);
        String result = null;
        try {
            List<Address> list = geocoder.getFromLocation(latitudedouble, longitudedouble, 1);
            if (list != null && list.size()>0) {
                Address address = list.get(0);
                result = address.getAddressLine(0) + ", " + address.getLocality();
                txtLat.setText(result);
            }
        } catch (IOException ex) {
            Logger.getLogger(MainActivity.class.getName()).log(Level.SEVERE, null, ex);
        }

     }
    public void onLocationChanged(Location location) {
        //find the text view for latitude
        txtLat = (TextView) findViewById(R.id.latitude);
        //change the text from the text view to the latitude of the device
        txtLat.setText("Latitude: " + location.getLatitude());
        //declare a variable to save the device's latitude
        latitudedouble = location.getLatitude();
        //find the text view for longitude
        txtLon = (TextView) findViewById(R.id.longitude);
        //change the text from the text view to the longitude of the device
        txtLon.setText("Longitude: " + location.getLongitude());
        //declare a variable to save the device's longitude
        longitudedouble = location.getLongitude();
    }

    @Override
    public void onProviderDisabled(String provider) {
        Log.d("Latitude","disable");
    }

    @Override
    public void onProviderEnabled(String provider) {
        Log.d("Latitude","enable");
    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {
        Log.d("Latitude","status");
    }
}
}

其他方法运行正常。它只是goButtonClicked方法下没有执行的代码