android-code-电量变化

IntentFilter filter = new IntentFilter();
        filter.addAction(Intent.ACTION_BATTERY_CHANGED);
        registerReceiver(mReceiver, filter);

private final BroadcastReceiver mReceiver = new BroadcastReceiver()
    {
        @Override
        public void onReceive(Context context, Intent intent)
        {
            String action = intent.getAction();
            if (action.equalsIgnoreCase(Intent.ACTION_BATTERY_CHANGED)) {
                int batteryLevel = intent.getIntExtra("level", 0);
                if (batteryLevel >= 50)
                    mBattery.setTextColor(Color.GREEN);
                else if (batteryLevel >= 30)
                    mBattery.setTextColor(Color.YELLOW);
                else
                    mBattery.setTextColor(Color.RED);
                mBattery.setText(String.format("%d%%", batteryLevel));
            }
        }
    };