Android 在片段中获取位置数据的最佳方法

我有一个检索用户位置的片段，一旦有了latt和long，它就会运行一个异步任务，根据lat和long更新listview

我的问题是，我有一个弹出对话框，上面说在异步任务运行时加载。但在此之前，我没有运行任何程序来通知用户正在找到他们的位置。所以有一个尴尬的停顿，除了一个快速的祝酒词告诉用户我正在找到他们的位置之外，什么都没有发生。在获得位置的同时，我可以运行另一个对话框吗

以下是我在片段中所做的：

package com.example.mike.beerportfoliomaterial;

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.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTabHost;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;

/**
 * Created by Mike on 3/8/14.
 */
public class FindBrewery extends Fragment implements LocationListener, GetNearbyBreweries.OnArticleSelectedListener {

    private TextView latituteField;
    private TextView longitudeField;
    LocationManager locationManager;
    private String provider;


    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        Context c = getActivity().getApplicationContext();
        locationManager =(LocationManager)activity.getSystemService(Context.LOCATION_SERVICE);

    }



    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

    }

    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        //todo change view
        View rootView = inflater.inflate(R.layout.beer_location_list,container, false);
        ((ActionBarActivity)getActivity()).getSupportActionBar().setTitle("Nearby Breweries");

        // Get the location manager
        // 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);

        Location location = null;

        Toast.makeText(getActivity(), "Getting your GPS Location", Toast.LENGTH_LONG).show();


        // Initialize the location fields
        if (location != null) {
            System.out.println("Provider " + provider + " has been selected.");
            onLocationChanged(location);
        } else {

        }


        return rootView;
    }




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

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

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

        //Toast.makeText(this, "Finding your loaction",Toast.LENGTH_SHORT).show();

        //call asycn task for location
        String url = "getDataURL&format=json&lat="+ lat +"&lng=" + lng + "&radius=50";


        Log.d("location" , "lat=" + lat);
        Log.d("location" , "lng=" + lng);

        //async task goes here
        new GetNearbyBreweries(this.getActivity()).execute(url);

        locationManager.removeUpdates(this);

        //todo: get json
        GetNearbyBreweries task = new GetNearbyBreweries(getActivity());
        task.setOnArticleSelectedListener(this);
        task.execute(url);



    }

    @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();
    }

    @Override
    public void onArticleSelected(String b){

        //code to execute on click
        Fragment Fragment_one;
        FragmentManager man= getFragmentManager();
        FragmentTransaction tran = man.beginTransaction();

        Fragment_one = new BreweryPage2();
        final Bundle bundle = new Bundle();
        bundle.putString("breweryIDSent", b);
        Fragment_one.setArguments(bundle);
        tran.replace(R.id.main, Fragment_one);//tran.
        tran.addToBackStack(null);
        tran.commit();

    }



}

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为什么不在列表为空的情况下进行简单的加载循环或其他操作？不知道该怎么做。我的所有对话框通常都在一个异步任务中，我在执行后将其忽略。我的意思不是作为一个对话框，而是作为空列表的占位符，直到它被填充为止