简单的介绍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;

//声明下面atteryReceiver类的对象
 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);

       //对按钮进行监听
        tb.setOnCheckedChangeListener(new OnCheckedChangeListener(){
        public void onCheckedChanged(CompoundButton compoundButton,
        boolean isChecked) {
        //获取电池电量
        if(isChecked){
        IntentFilter filter=new

       //传入控电池电量的广播消息
        IntentFilter(Intent.ACTION_BATTERY_CHANGED);

       //注册BroadcastReceiver
        registerReceiver(receiver, filter);

        }else {
        //停止获取电池电量
        unregisterReceiver(receiver);
        tv.setText(null);
        }
        }
        });
        }

      //创建BatteryReceiver的类继承BroadcastReceiver
        private class BatteryReceiver extends BroadcastReceiver{
        @Override

       //负责接收广播并且处理的方法
        public void onReceive(Context context, Intent intent) {

        //获得当前电量
        int current=intent.getExtras().getInt("level");

        //获得总电量
        int total=intent.getExtras().getInt("scale");

        //运算出电池电量的百分比
        int percent=current*100/total;
        tv.setText("现在的电量是"+percent+"%。");
        }
        }
        }