我制作了一个应用程序来检测我连接到哪个 wifi，并根据它在静音和非静音之间更改声音模式。不过，我想知道，我这样做的方式是否合理。
我把它作为一项服务，因为我希望它一直检查。在服务内部，我在 onStartCommand() 方法中注册了一个广播接收器，并在 onDestroy() 中取消注册它。它不受约束。广播接收器监听连接的变化。
我真正的问题是这是否是一种“经济上”的好方法？还是在服务运行时使用所有电池/内存？
我的（相关）服务源代码：
import java.util.ArrayList;
import java.util.List;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.SharedPreferences;
import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
import android.media.AudioManager;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.net.wifi.WifiManager;
import android.os.IBinder;
import android.os.Vibrator;
import android.util.Log;
import android.widget.Toast;
public class CheckService extends Service {
public static final String MY_SETTINGS = "MySettings";
private ConnectivityReceiver receiver = null;
public static boolean isRunning = false;
private WifiManager wifi;
private AudioManager audio_mngr;
private SharedPreferences settings;
private List<Network> networks;
private String SSID;
@Override
public IBinder onBind(Intent arg0) {
// TODO Auto-generated method stub
return null;
}
@Override
public void onCreate() {
// TODO Auto-generated method stub
super.onCreate();
receiver = new ConnectivityReceiver();
wifi = (WifiManager)getSystemService(Context.WIFI_SERVICE);
audio_mngr = (AudioManager) getBaseContext().getSystemService(Context.AUDIO_SERVICE);
settings = getSharedPreferences(MY_SETTINGS, 0);
networks = getAllNetworks();
settings.registerOnSharedPreferenceChangeListener(new OnSharedPreferenceChangeListener(){
public void onSharedPreferenceChanged(
SharedPreferences sharedPreferences, String key) {
networks = getAllNetworks();
}
});
}
@Override
public int onStartCommand(Intent intent, int flags, int startId)
{
super.onStartCommand(intent, flags, startId);
registerReceiver(receiver,new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION));
isRunning = true;
return START_STICKY;
}
@Override
public void onDestroy()
{
super.onDestroy();
//Stop the Background thread
isRunning = false;
unregisterReceiver(receiver);
//Announcement about stopping
Toast.makeText(this, "Stopping the Demo Service", Toast.LENGTH_SHORT).show();
}
public List<Network> getAllNetworks() {
List<Network> temp = new ArrayList<Network>();
String[] data = settings.getString("networks", "").split(",");
if(data.length>1)
{
for(int i=1; i<data.length-1; i+=2)
{
temp.add(new Network(data[i],data[i+1]));
}
}
return temp;
}
private class ConnectivityReceiver extends BroadcastReceiver{
@Override
public void onReceive(Context context, Intent intent) {
NetworkInfo info = intent.getParcelableExtra(ConnectivityManager.EXTRA_NETWORK_INFO);
if(null != info)
{
if(info.getState()==NetworkInfo.State.CONNECTED)
{
SSID = wifi.getConnectionInfo().getSSID();
for(Network n : networks)
{
if(n.getSSID().equals(SSID))
{
if(n.isQuiet()) setQuiet();
else setLoud();
break;
}
}
}
}
}
}
private void setQuiet()
{
Vibrator v = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
audio_mngr .setRingerMode(AudioManager.RINGER_MODE_VIBRATE);
v.vibrate(300);
makeNotification(SSID,"Vibrate mode on!",R.drawable.sound_off);
}
private void setLoud()
{
Vibrator v = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
audio_mngr .setRingerMode(AudioManager.RINGER_MODE_NORMAL);
v.vibrate(300);
makeNotification(SSID,"Normal mode on!", R.drawable.sound_on);
}
private void makeNotification(String network, String loudness, int icon)
{
NotificationManager notificationManager = (NotificationManager)
getSystemService(NOTIFICATION_SERVICE);
CharSequence tickerText = "Mode has been changed!";
long when = System.currentTimeMillis();
final Notification notification = new Notification(icon, tickerText, when);
Context context = getApplicationContext();
CharSequence contentTitle = network;
CharSequence contentText = loudness;
Intent notificationIntent = new Intent(this, CheckService.class);
PendingIntent contentIntent = PendingIntent.getActivity(this, 0, notificationIntent, 0);
notification.setLatestEventInfo(context, contentTitle, contentText, contentIntent);
final int HELLO_ID = 1;
notification.flags |= Notification.FLAG_AUTO_CANCEL;
notificationManager.notify(HELLO_ID, notification);
}
}