專案中需要這樣的要求：
啟動一個服務一直在背後監聽當前位置變化，如果進入到離某個地點n千米內，發出一個Notification提醒使用者附近有什麼什麼......

這裡我採用的策略是這樣的：

首先監聽網路，如果聯網了就啟動距離監聽服務，否則關閉距離監聽服務。因為網路一旦斷了，何談距離變化？
其次，是否需要開機自啟動網路監聽，這樣也就等於啟動了距離監聽服務。
其三，一旦進入到某個範圍之內，就馬上關閉距離監聽服務，否則會不停的提醒，使用者會覺得很煩。
基於以上步驟，首先實現一個距離監聽服務

package com.mobovip.app;

import java.text.DecimalFormat;
import java.util.ArrayList;

import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;
import android.util.Log;

public class LocationService extends Service{

	private Context context;
	public static ArrayList<Store> stores=new ArrayList<Store>();
	public static double distance = 3;//7430km
	private LocationManager locationManager;
	private NotificationManager notificationManager;
	@Override
	public IBinder onBind(Intent intent) {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public void onCreate() {
		super.onCreate();
		context = this;
		locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
		
//		if(locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)){
//			locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,1000, 1f, locationListener);
//		}else{
			locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER,1000, 1f,locationListener);
//		}
		
//		Location location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);     
//        if(location != null){
//        	checkDistance(location);
//        }     
        
	}

	
	private final LocationListener locationListener = new LocationListener() {
		//當座標改變時觸發此函式，如果Provider傳進相同的座標，它就不會被觸發
	    public void onLocationChanged(Location location) { 
	        // log it when the location changes
	        if (location != null) {
	        	checkDistance(location);
	        }
	    }

	    // Provider被disable時觸發此函式，比如GPS被關閉
	    public void onProviderDisabled(String provider) {
	    }

	    //  Provider被enable時觸發此函式，比如GPS被開啟
	    public void onProviderEnabled(String provider) {
	    }

	    // Provider的在可用、暫時不可用和無服務三個狀態直接切換時觸發此函式
	    public void onStatusChanged(String provider, int status, Bundle extras) {
	    }
	};
	
	@Override
	public void onDestroy() {
		super.onDestroy();
		if(locationManager!=null){
			locationManager.removeUpdates(locationListener); 
			locationManager=null;
		}
	}

	private void checkDistance(Location location) {
		if (location != null) {
			float[] results = new float[1];
			for (Store store : stores) {
				Location.distanceBetween(location.getLatitude(),
						location.getLongitude(), store.getLatitude(),
						store.getLongitude(), results);
				float result=(results[0] / 1000);//km
				if (result < distance) {
					
					
					showNotification(store);
					
					stopSelf();//不要頻繁的提醒
					break;
				}
			}
		}
	}


	private static final int NOTIFY_ID = 0;
	private void showNotification(Store store) {
		notificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
		
		Intent intent = new Intent(this, BGR.class);
//		intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP|Intent.FLAG_ACTIVITY_NEW_TASK);
		intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
		PendingIntent pendingIntent = PendingIntent.getActivity(this, 0,
				intent, PendingIntent.FLAG_UPDATE_CURRENT);// FLAG_ONE_SHOT
		Notification notification = new Notification.Builder(context)
				.setTicker(context.getString(R.string.app_name, ""))
				.setContentTitle(store.getStoreName()+"("+store.getDistance()+")")
				.setContentText(store.getStoreAddress())
				.setContentIntent(pendingIntent)
				.setSmallIcon(R.drawable.ic_launch_notify)
				.setAutoCancel(true)
				.setWhen(System.currentTimeMillis())
				.setDefaults(Notification.DEFAULT_ALL)
				.getNotification();
		
		notificationManager.notify(NOTIFY_ID, notification);
	}
	
}

 

網路監聽服務，其實註冊了一個廣播，監聽手機CONNECTIVITY_ACTION動作即可

package com.mobovip.app;

import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.IBinder;

public class NetworkStateService extends Service {

	private static final String tag = "tag";
	private BroadcastReceiver mReceiver = new BroadcastReceiver() {

		@Override
		public void onReceive(Context context, Intent intent) {
			String action = intent.getAction();
			if (action.equals(ConnectivityManager.CONNECTIVITY_ACTION)) {
				ConnectivityManager manager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
				NetworkInfo info = manager.getActiveNetworkInfo();
				if (info != null && info.isAvailable()) {
					Intent service = new Intent(context, LocationService.class);
					startService(service);
				} else {
					Intent service = new Intent(context, LocationService.class);
					stopService(service);
				}
			}
		}
	};

	@Override
	public boolean onUnbind(Intent intent) {
		// TODO Auto-generated method stub
		return super.onUnbind(intent);
	}

	@Override
	public IBinder onBind(Intent intent) {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public void onCreate() {
		super.onCreate();
		IntentFilter mFilter = new IntentFilter();
		mFilter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
		registerReceiver(mReceiver, mFilter);
	}

	@Override
	public void onDestroy() {
		super.onDestroy();
		unregisterReceiver(mReceiver);
	}

	@Override
	public int onStartCommand(Intent intent, int flags, int startId) {
		return super.onStartCommand(intent, flags, startId);
	}

}

 

如有必要加上開機啟動

package com.mobovip.app;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;

/**
 * BootReceiver
 * 
 * @author NGJ
 * 
 */
public class BootReceiver extends BroadcastReceiver {

	@Override
	public void onReceive(Context context, Intent intent) {
		// TODO Auto-generated method stub
		Intent i = new Intent(context, NetworkStateService.class);
		i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
		context.startService(i);
	}

}
 

以上service，BroadcastReceiver都需要註冊，再加上網路許可權等

<service android:enabled="true" android:name="com.mobovip.app.NetworkStateService" />
        <service android:enabled="true" android:name="com.mobovip.app.LocationService" />
        <!-- 
        <receiver android:name="com.mobovip.app.BootReceiver" >
            <intent-filter>
                <action android:name="android.intent.action.BOOT_COMPLETED" />
            </intent-filter>
        </receiver>
         -->