我正在构建有关电池指示器的应用程序,我正在使用此帖子中的代码。
Getting battery status even when the application is closed
应用程序关闭时工作正常,但当应用程序处于活动状态或前台时,它无效或无法发送任何广播。
这是我开始服务的主要活动
public class Main extends Activity {
private MyService service;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
if (service == null) {
Intent i = new Intent(this, MyService.class);
startService(i);
}
finish();
}
}
以下是服务代码。
public class MyService extends Service{
@Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return null;
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.d("MyService", "onStartCommand");
// do not receive all available system information (it is a filter!)
final IntentFilter battChangeFilter = new IntentFilter(
Intent.ACTION_BATTERY_CHANGED);
// register our receiver
this.registerReceiver(this.batteryChangeReceiver, battChangeFilter);
return super.onStartCommand(intent, flags, startId);
}
private final BroadcastReceiver batteryChangeReceiver = new BroadcastReceiver() {
@Override
public void onReceive(final Context context, final Intent intent) {
checkBatteryLevel(intent);
}
};
private void checkBatteryLevel(Intent batteryChangeIntent) {
// some calculations
final int currLevel = batteryChangeIntent.getIntExtra(
BatteryManager.EXTRA_LEVEL, -1);
final int maxLevel = batteryChangeIntent.getIntExtra(
BatteryManager.EXTRA_SCALE, -1);
final int percentage = (int) Math.round((currLevel * 100.0) / maxLevel);
if(percentage==100)
{
Intent intent = new Intent(getBaseContext(), Last.class);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
getApplication().startActivity(intent);
}
// do not forget to unregister
unregisterReceiver(batteryChangeReceiver);
} }
当以下活动开始时,我没有收到任何广播。
public class Last extends Activity {
Button btnCancel;
Uri notification;
Ringtone r;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_last);
notification = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_RINGTONE);
r = RingtoneManager.getRingtone(getApplicationContext(), notification);
r.play();
btnCancel = (Button) findViewById(R.id.stopsound);
btnCancel.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
r.stop();
}
});
} }
答案 0 :(得分:0)
据我了解, 当您第一次启动应用程序时,您什么也看不到,只启动服务并注册广播接收器。当电池电量改变时,方法 checkBatteryLevel()正在呼叫,广播接收器将被取消注册。结果,您从未收到过新的电池电量变化。