Android中吐司目前电池电量

/** *  * @author chrp * *土司当当电池电量 */public class MainActivity extends Activity {	class BtteryReceiver extends BroadcastReceiver {		@Override		public void onReceive(Context context, Intent intent) {			// TODO Auto-generated method stub			System.out.println("+++++++++++++++++++++++");			// 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", 0);				// 把它转换成百分比				String content = ("电池电量为" + ((level * 100) / scale) + "%");				int key = ((level * 100) / scale);				switch (key) {				case 100:					Toast.makeText(context, "电池已经充满", Toast.LENGTH_LONG).show();					break;				case 50:					Toast.makeText(context, "电池已经使用一半", Toast.LENGTH_LONG)							.show();					break;				case 30:					Toast.makeText(context, "电池已到30%了", Toast.LENGTH_LONG)							.show();					break;				case 40:					Toast.makeText(context, "电池已到31%了", Toast.LENGTH_LONG)							.show();					break;				case 10:					Toast.makeText(context, "电池不足10%", Toast.LENGTH_LONG)							.show();					break;				case 9:					Toast.makeText(context, "电池不足9%", Toast.LENGTH_LONG).show();					break;				case 5:					Toast.makeText(context, "电池不足5%", Toast.LENGTH_LONG).show();					break;				}			}		}	}