簡單的介紹BroadcastReceiver的使用方法

public class BatteryActivity extends Activity {
    /** Called when the activity is first created. */
 private ToggleButton tb=null;
 private TextView tv=null;

//聲明下面atteryReceiver類的對象
 private BatteryReceiver receiver=null;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        //setContentView(R.layout.main);
        receiver=new BatteryReceiver();
        tv=(TextView)findViewById(R.id.tv);
        tb=(ToggleButton)findViewById(R.id.tb);

       //對按鈕進行監聽
        tb.setOnCheckedChangeListener(new OnCheckedChangeListener(){
        public void onCheckedChanged(CompoundButton compoundButton,
        boolean isChecked) {
        //獲取電池電量
        if(isChecked){
        IntentFilter filter=new

       //傳入控電池電量的廣播消息
        IntentFilter(Intent.ACTION_BATTERY_CHANGED);

       //註冊BroadcastReceiver
        registerReceiver(receiver, filter);

        }else {
        //停止獲取電池電量
        unregisterReceiver(receiver);
        tv.setText(null);
        }
        }
        });
        }

      //創建BatteryReceiver的類繼承BroadcastReceiver
        private class BatteryReceiver extends BroadcastReceiver{
        @Override

       //負責接收廣播並且處理的方法
        public void onReceive(Context context, Intent intent) {

        //獲得當前電量
        int current=intent.getExtras().getInt("level");

        //獲得總電量
        int total=intent.getExtras().getInt("scale");

        //運算出電池電量的百分比
        int percent=current*100/total;
        tv.setText("現在的電量是"+percent+"%。");
        }
        }
        }