复制代码 代码如下:

/**

*

* @author chrp

*

*显示当前电池电量

*/

public class MainActivity extends Activity {

private TextView tv;

/**

* 广播接受者

*/

class BatteryReceiver extends BroadcastReceiver{

@Override

public void onReceive(Context context, Intent intent) {

// TODO Auto-generated method stub

//判断它是否是为电量变化的Broadcast Action

if(Intent.ACTION_BATTERY_CHANGED.equals(intent.getAction())){

//获取当前电量

int level = intent.getIntExtra("level", 0);

//电量的总刻度

int scale = intent.getIntExtra("scale", 100);

//把它转成百分比

tv.setText("电池电量为"+((level*100)/scale)+"%");

}

}

}

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

//setContentView(R.layout.activity_main);

tv = new TextView(this);

tv.setText("chrp");

this.setContentView(tv);

//注册广播接受者java代码

IntentFilter intentFilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);

//创建广播接受者对象

BatteryReceiver batteryReceiver = new BatteryReceiver();

//注册receiver

registerReceiver(batteryReceiver, intentFilter);

}