Android位置服務：我可以爲GPS和網絡位置使用單個位置監聽器嗎？

Question

我是否爲網絡位置和gps位置註冊單個locationlistener對象，還是爲每個位置創建單獨的一個？

Answer 1

您可以對兩者使用相同的偵聽器。

當您獲得onLocationChanged()或onStatusChanged()回調時，您可以檢查傳入參數（位置或提供商）以確定回叫的來源（即：網絡或GPS）。

Answer 2

使用下面的類來檢索位置。它會選擇最佳的供應商和返回的緯度和經度：

package com.test.location; 

import android.app.ProgressDialog; 
import android.content.Context; 
import android.content.DialogInterface; 
import android.content.DialogInterface.OnCancelListener; 
import android.location.Criteria; 
import android.location.Location; 
import android.location.LocationListener; 
import android.location.LocationManager; 
import android.os.Bundle; 
import android.widget.Toast; 

public class LocationPicker implements LocationListener, OnCancelListener{ 

private Context ctx; 
private LocationManager locationMgr; 
private boolean stopFlag; 
private ProgressDialog dialog; 

public LocationPicker(Context ctx) { 
    this.ctx = ctx; 
} 

public void retrieveLocation() { 

    String locCtx = Context.LOCATION_SERVICE; 

    locationMgr = (LocationManager) ctx.getSystemService(locCtx); 

    Criteria criteria = new Criteria(); 
    criteria.setAccuracy(Criteria.ACCURACY_FINE); 
    criteria.setAltitudeRequired(false); 
    criteria.setBearingRequired(false); 
    criteria.setCostAllowed(true); 
    criteria.setPowerRequirement(Criteria.POWER_LOW); 

    String provider = locationMgr.getBestProvider(criteria, true); 

    locationMgr.requestLocationUpdates(provider, 0, 0, this); 

    Runnable showWaitDialog = new Runnable() { 

     @Override 
     public void run() { 
      while (!stopFlag) { 
       // Wait for first GPS Fix (do nothing until loc != null) 
      } 
      // After receiving first GPS Fix dismiss the Progress Dialog 
      dialog.dismiss(); 
     } 
    }; 

    dialog = ProgressDialog.show(ctx, "Please wait...", "Retrieving GPS data...", true); 
    dialog.setCancelable(true); 
    dialog.setOnCancelListener(this); 
    Thread t = new Thread(showWaitDialog); 
    t.start(); 
} 

@Override 
public void onLocationChanged(Location location) { 
    if (location != null) { 
     double latitude = location.getLatitude(); 
     double longitude = location.getLongitude(); 
     stopFlag = true; 
     Toast.makeText(ctx, "Latitude : " + latitude + " Longitude : " + longitude , Toast.LENGTH_LONG).show(); 
    } 
    locationMgr.removeUpdates(this); 
} 

@Override 
public void onProviderDisabled(String provider) { 
// Toast.makeText(ctx, "GPS Disabled", Toast.LENGTH_LONG).show(); 
// 
// Intent intent = new Intent(android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS); 
// ctx.startActivity(intent); 
} 

@Override 
public void onProviderEnabled(String provider) { 
// Toast.makeText(ctx, "GPS Enabled", Toast.LENGTH_SHORT).show(); 
// 
// ctx.startActivity(new Intent(ctx, LocationPickerActivity.class)); 
} 

@Override 
public void onStatusChanged(String provider, int status, Bundle extras) { 

} 

@Override 
public void onCancel(DialogInterface dialog) { 
    stopFlag = true; 
    locationMgr.removeUpdates(this); 
} 
    } 

的創造上面的類後，只需調用下面的方法，它會返回經緯度:::

LocationPicker lp = new LocationPicker(this); 
    lp.retrieveLocation(); 

注意：自定義位置偵聽器也包含進度對話框。